Document ID: NHTSA-2008-0068-0001
Agency: nhtsa
Document Type: Rule
Title: Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems; Controls and Displays
Posted Date: 2008-09-22T04:00Z

[Federal Register: September 22, 2008 (Volume 73, Number 184)]
[Rules and Regulations]               
[Page 54526-54543]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22se08-8]                         

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2008-0068]
RIN 2127-AK19

 
Federal Motor Vehicle Safety Standards; Electronic Stability 
Control Systems; Controls and Displays

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation (DOT).

ACTION: Final rule; response to petitions for reconsideration.

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SUMMARY: On April 6, 2007, NHTSA published a final rule establishing a 
new Federal motor vehicle safety standard requiring light vehicles to 
be equipped with electronic stability control systems. The final rule 
was established as part of a comprehensive plan for reducing the 
serious risk of rollover crashes and the risk of death and serious 
injury in those crashes. This document responds to several petitions 
for reconsideration of the final rule. After carefully considering the 
issues raised, the agency is granting some aspects of the petitions, 
and denying some aspects. This document amends the final rule 
accordingly. This document also fulfills the obligations of the United 
States with respect to initiating rulemaking in order to comply with 
the global technical regulation (GTR) for ESC, adopted on June 26, 
2008.

DATES: This rule is effective October 22, 2008.

ADDRESSES: Petitions for reconsideration should refer to the docket 
number and be submitted to: Administrator, National Highway Traffic 
Safety Administration, 1200 New Jersey Avenue, SE., West Building, 4th 
Floor, Washington, DC 20590. Note that all documents received will be 
posted without change to the docket, including any personal information 
provided. Please see the Privacy Act discussion under section IV on 
Rulemaking Analyses and Notices below.

FOR FURTHER INFORMATION CONTACT: For technical issues, contact 
Nathaniel Beuse, Office of Crash Avoidance Standards, by telephone at 
(202) 366-4931, or by fax at (202) 366-7002. For legal issues, contact 
Rebecca Yoon, Office of the Chief Counsel, by telephone at (202) 366-
2992, or by fax at (202) 366-3820.
    Both persons may be reached by mail at the following address: 
National Highway Traffic Safety Administration, U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., Washington, DC 20590.

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Summary of Final Rule; Response to Petitions for Reconsideration
II. Background
    A. Benefits of ESC
    B. April 2007 Final Rule
    C. Summary of Petitions for Reconsideration to the Final Rule
III. Discussion and Analysis of Responses to Petitions for 
Reconsideration
    A. Telltale Issues
    1. Use of a Two-Part ``ESC Off'' Telltale

[[Page 54527]]

    2. Inclusion of ESC-Related Systems in ESC Malfunction Telltale 
Operational Requirements
    3. Compliance Dates for Telltale Requirements
    B. Multi-Function ESC Controls
    C. ``ESC Off'' Control Labeling
    D. Disconnection of the Optional ``ESC Off'' Control
    E. Automatic Return of ESC System to ``On'' Mode for Each 
Ignition Cycle
    F. Low-Speed Threshold for ESC Operation
    G. Fault Detection and Cancellation Test Procedures
    H. Effective Dates for Amended Procedures and Requirements
    I. Inclusion of Roll Stability Control in the Scope of the Final 
Rule
    J. NHTSA's Rulemaking Analysis on Preemption
    K. International Harmonization and the Global Technical 
Regulation on ESC
IV. Rulemaking Analyses and Notices
V. Regulatory Text

I. Summary of Final Rule; Response to Petitions for Reconsideration

    In this document, NHTSA responds to petitions for reconsideration 
of its April 2007 final rule concerning electronic stability control 
(ESC) systems. That rule established a new Federal Motor Vehicle Safety 
Standard (FMVSS) No. 126, Electronic Stability Control Systems, which 
sets forth requirements for these systems on new light vehicles, to be 
applicable to all light vehicles by September 1, 2011.
    We are granting some of the petitions in part. In granting these 
petitions, today's final rule makes several changes to the regulatory 
text of 49 CFR 571.126, Electronic Stability Control Systems, and of 49 
CFR 571.101, Controls and Displays. These are generally minor changes, 
all of which are consistent with agency's goal in the original final 
rule to encourage rapid installation of this life-saving technology. 
Changes to the regulatory text are summarized below.
    We are denying a petition from the American Association for Justice 
(AAJ) to withdraw preemption language from the regulatory analysis 
section of the final rule, and to expand the scope of the final rule to 
require roll stability control in addition to ESC.

Summary of Changes

    1. In FMVSS No. 101, to avoid confusion regarding the compliance 
date for ESC telltale requirements, the agency is adding ``As of 
September 1, 2011'' in the relevant places to paragraphs S5.5.2 and 
S5.5.5 and Table 1.
    2. To clarify that related vehicle systems may use the ESC 
malfunction telltale and that the ESC malfunction telltale may flash to 
indicate operation of related systems, the agency is slightly revising 
S5.3.3 and adding a new S5.3.10 to FMVSS No. 126.
    3. For purposes of clarification, the agency is revising S5.3.9 in 
FMVSS No. 126 to remove language that might be interpreted to require 
the ESC malfunction telltale to illuminate to indicate a disconnection 
of the ESC Off control.
    4. To simplify the telltale requirements, we are also allowing two-
part telltales that are able to display both the ``ESC malfunction'' 
and ``ESC Off'' messages.
    5. To avoid any potential negative safety consequences of requiring 
vehicles to restart in 2-wheel drive when they are using 4-wheel drive 
to navigate difficult terrain, the agency is expanding the exception to 
S5.4.1's key cycle automatic ESC reactivation requirement in FMVSS No. 
126. We are revising S5.4.1 to tie the exception directly to the low-
range 4-wheel drive configuration, and adding a definition for 4-wheel 
drive low-range configuration. For the same reason, the agency is 
revising S5.4.1's default mode requirement to refer to ESC modes within 
the same drive configuration.
    6. FMVSS No. 126 requires that ESC systems meet two fundamental 
performance criteria, stability and responsiveness. It is possible that 
these performance criteria can conflict in some drive 
configurations,\1\ thereby creating ambiguity with respect to the 
existing requirement in S5.4.1 that refers to an ESC mode that 
satisfies the performance requirements ``by the greatest margin.'' To 
address this, the agency is revising S5.4.1 to specify that upon 
vehicle restart, ESC systems must revert to the manufacturer's original 
default mode for that drive configuration. These modes, with some 
exceptions as noted, must meet the stability and responsiveness 
requirements of the standard.
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    \1\ This is a basic problem of vehicle dynamics: in order to be 
stable, a vehicle should experience less side-to-side movement, but 
in order to be responsive, a vehicle must be able to move side-to-
side as necessary. Proper and safe vehicle handling, which ESC 
facilitates, must strike a balance between stability and 
responsiveness depending on the situation. Thus, it is possible that 
increasing stability in response to driving conditions could 
decrease responsiveness--yet S5.4.1 as written requires both 
stability and responsiveness to be satisfied by the greatest margin, 
which is not always possible or desirable. This is why the agency is 
revising this section.
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    7. To clarify that ESC systems need not be operational before they 
have initialized, the agency is adding S7.10.2's initialization 
procedure to S7.10.4 and S6.3.1 of FMVSS No. 126.
    8. In recognition of the fact that many current ESC system designs 
cannot hold a malfunction in memory when the ignition is cycled off and 
then back on as required, S7.10.3 of FMVSS No. 126 will not be 
mandatory until September 1, 2011.
    9. To gain the substantial safety benefits of ESC as quickly as 
possible, and because we anticipate no negative safety consequences, 
the agency is accommodating current ESC systems by changing the low-
speed cutoff for ESC operation from 15 km/h (9.3 mph) to 20 km/h (12.4 
mph) and adding a brake application to all initialization procedures in 
FMVSS No. 126.
    10. To clarify that the final rule did not prohibit multi-function 
ESC controls, the agency is adding language to that effect in S5.4 of 
FMVSS No. 126.
    11. To clarify changes made to the regulatory text, the agency is 
adding definitions for ``drive configuration'' and ``mode'' to S4 of 
FMVSS No. 126.

II. Background

A. Benefits of ESC

    Electronic stability control, or ESC, systems use automatic 
computer-controlled braking of individual wheels to assist the driver 
in maintaining control in critical driving situations in which the 
vehicle is beginning to lose directional stability at the rear wheels 
(spin out) or directional control at the front wheels (plow out). 
NHTSA's crash data study of existing vehicles equipped with ESC 
demonstrated that these systems reduce fatal single-vehicle crashes of 
passenger cars by 36 percent and fatal single-vehicle crashes of sport 
utility vehicles (SUVs) by 63 percent.\2\ NHTSA estimates that ESC has 
the potential to prevent 70 percent of the fatal passenger car 
rollovers and 88 percent of the fatal SUV rollovers that would 
otherwise occur in single-vehicle crashes.\3\
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    \2\ Dang, J., Statistical Analysis of the Effectiveness of 
Electronic Stability Control (ESC) Systems--Final Report, DOT HS 810 
794, U.S. Department of Transportation, Washington, DC (July 2007). 
Available at Docket No. NHTSA-2007-28629, item 2.
    \3\ Id.
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B. April 2007 Final Rule

    On April 6, 2007, NHTSA published a final rule establishing the new 
Federal Motor Vehicle Safety Standard (FMVSS) No. 126, Electronic 
Stability Control Systems, which sets forth requirements for these 
systems on new light vehicles.\4\ FMVSS No. 126 contains performance 
requirements that include both definitional and dynamic testing 
elements. These elements together ensure that ESC systems intervene

[[Page 54528]]

properly to limit oversteer and understeer in order to provide the 
level of yaw (directional) stability associated with the high level of 
safety benefits observed in crash data studies of ESC-equipped 
vehicles. FMVSS No. 126 also requires a standardized set of ESC 
telltales and controls.
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    \4\ Docket No. NHTSA-2007-27662, item 1; 72 FR 17236 (Apr. 6, 
2007).
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    The new standard's requirements for yaw stability control (that is, 
the parts of the standard with the biggest potential to prevent 
crashes) can be met by most ESC-equipped vehicles currently being 
manufactured. However, none of those vehicles appear to use the exact 
set of telltales and controls required by the new standard. In order to 
provide the American public with the substantial safety benefits of ESC 
as soon as possible, NHTSA accelerated the phase-in schedule in the 
final rule as compared to the schedule proposed in the September 2006 
notice of proposed rulemaking (NPRM),\5\ but deferred the telltale and 
display requirements until the end of the phase-in. Thus, the final 
rule set the phase-in as:
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    \5\ Docket No. NHTSA-2006-25801, item 1; 71 FR 54712 (Sept. 18, 
2006).
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     55 percent of a manufacturer's light vehicles manufactured 
during the period from September 1, 2008 to August 31, 2009 are 
required to comply with the standard;
     75 percent from September 1, 2009 to August 31, 2010;
     95 percent from September 1, 2010 to August 31, 2011; and
     All light vehicles thereafter.

This compares to the NPRM's proposal for a 30/60/90/all phase-in 
schedule over the same time period. The agency noted in the final rule 
preamble that some manufacturers will have to depend on carry-forward 
credits for vehicles with complying ESC systems manufactured after June 
5, 2007 (the effective date of the final rule) in order to meet the 
accelerated phase-in schedule.
    Regarding the deferral of the telltale and display requirements 
until the end of the phase-in period, although NHTSA perceived certain 
advantages with standardizing these requirements, we concluded that it 
was not practicable to implement the necessary changes under the 
accelerated phase-in schedule, and we were not willing to delay the 
phase-in (and the expected safety benefits) for this reason alone. 
Accordingly, the agency prefaced many of the provisions in FMVSS No. 
126 dealing with telltales and displays with the phrase ``as of 
September 1, 2011.'' However, after the final rule was published, we 
discovered that that phrase had been inadvertently omitted from two of 
the relevant provisions. NHTSA published a correction notice on June 
22, 2007 to address this issue.\6\
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    \6\ Docket No. NHTSA-2007-27662, item 9; 72 FR 34409 (Jun. 22, 
2007).
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C. Summary of Petitions for Reconsideration to the Final Rule

    Four parties petitioned for reconsideration of the April 6, 2007 
final rule: the American Association for Justice (AAJ); \7\ Porsche 
Cars North America, Inc. (Porsche); \8\ and in a joint petition, the 
Alliance of Automotive Manufacturers and the Association of 
International Automobile Manufacturers (Alliance/AIAM).\9\ Chrysler 
also submitted a letter supporting revised recommendations submitted by 
the Alliance/AIAM following its original petition for 
reconsideration.\10\ Most of the issues presented by the manufacturer 
petitioners addressed details of the requirements for controls and 
displays and their effect on phase-in requirements. AAJ petitioned 
NHTSA to change language in the final rule preamble concerning the 
preemptive effect of Federal regulations, and also petitioned that the 
scope of the final rule be expanded to require roll stability control 
in addition to ESC that focuses on yaw stability.
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    \7\ Id., item 6.
    \8\ Id., item 4.
    \9\ Id., item 5.
    \10\ Chrysler letter, id., item 12; Alliance/AIAM revised 
recommendations, id., item 10.
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    The next section addresses the petitions issue by issue, and 
provides the agency's response for each issue.

III. Analysis of and Response to Petitions for Reconsideration

A. Telltale Issues

1. Use of a Two-Part ``ESC Off'' Telltale
    The final rule requires an ESC malfunction telltale identified by 
the ISO symbol for ESC or the abbreviation ``ESC.'' It also requires a 
second telltale to identify when the ESC system has been turned off by 
the driver. That telltale must be identified by the ISO symbol for ESC 
with the word ``Off'' below it, or the words ``ESC Off.''
    Porsche Cars North America, Inc. (Porsche) originally commented to 
the NPRM that instead of requiring two completely separate telltales 
for the ESC malfunction and ESC Off messages, the rule should allow for 
a partial telltale with just the word ``Off'' adjacent to the ESC 
malfunction telltale. The ESC Off message would be created by 
illuminating the ``Off'' telltale and the ESC malfunction telltale 
simultaneously. The object of this design would be to save space on the 
instrument panel.
    NHTSA did not include Porsche's suggested change in the final rule 
because we thought that allowing a partial telltale would have created 
a conflict with the requirement that the ESC Off status be indicated by 
the telltale whenever the driver has manually disabled the ESC. In the 
case where the ESC system detects a fault when it is in the manually 
disabled state, the ``Off'' part of the partial, two-part telltale 
would have to be extinguished to indicate the ESC malfunction.\11\
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    \11\ See 72 FR 17236, 17276 (Apr. 6, 2007).
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    Porsche petitioned for reconsideration on NHTSA's decision on two-
part telltales. Specifically, Porsche explained in its petition that 
``in the rare case when a malfunction occurs after the driver has 
manually disabled the system,'' its ESC system ``would operate so that 
the malfunction event results in the manual control functionality being 
automatically disabled.'' Thus, the ``ESC Off'' message would no longer 
be correct, because the ESC would have overridden the manual 
disablement; and the ``ESC Malfunction'' message would be correct. 
Porsche petitioned that NHTSA clarify that a two-part telltale would 
not be prohibited in the situation it described, and requested that 
NHTSA add a footnote to Table 1 of FMVSS No. 101 that a two-part ESC 
Off telltale is acceptable if the parts are configured as depicted for 
the symbol or phrase stipulated by the table to identify the ESC Off 
telltale.
    Porsche also requested that a footnote be added to Table 1 
indicating that the ``ESC Off'' telltale ``is mandatory only in the 
event that the system is manually disabled by the driver.''
    Agency Response: We are granting this petition in part and denying 
in part. We have considered the two-part telltale issue further and 
have concluded that there will be no significant safety consequences 
from allowing manufacturers to use a two-part telltale instead of 
entirely separate telltales for ESC malfunction and ESC Off. The 
situation that Porsche describes, where the ESC system overrides the 
driver's ``Off'' command if a malfunction occurs while the ESC system 
is disabled, would already meet the requirements of the final rule. 
This is because in that situation, it would be correct to extinguish 
the ``Off'' portion of the two-part telltale (because ESC would no 
longer be off), and leave only the ``ESC'' portion illuminated. Thus, 
for that particular case, a two-part telltale would satisfy NHTSA's 
original requirement

[[Page 54529]]

that the ESC malfunction message be displayed without interfering with 
the ESC Off message, because the ESC would no longer be manually 
disabled.
    More generally, if an ESC system malfunction occurs after a driver 
has disabled ESC, requiring both telltales to illuminate at the same 
time, both telltales would convey essentially the same message to the 
driver: that ESC functionality has been reduced or eliminated. Because 
of this, and because we anticipate that ESC systems will likely only 
rarely malfunction after they have been manually disabled, upon further 
consideration we do not believe that requiring both messages to be 
presented simultaneously (and thus prohibiting two-part telltales) is 
necessary for safety. To build on Porsche's example, if an ESC system 
uses a two-part telltale that illuminates both parts to convey the 
``ESC Off'' message, but does not override the driver's ``Off'' command 
if a malfunction occurs while ESC is disabled, the telltale would 
simply continue to display ``ESC Off,'' which would indicate to the 
driver that ESC functionality is reduced. Because the final rule 
requires ESC to return to ``on'' with each ignition cycle, the ``Off'' 
telltale must be extinguished, and the malfunction telltale can simply 
be illuminated at that point. We believe that this would not present 
significant safety problems, since the driver would still be notified 
promptly upon restarting the engine that the ESC malfunction exists. 
There would be no period in which the two-part telltale failed to 
convey the basic message that ESC functionality was reduced or 
eliminated.
    Implementing this change necessitates revision of paragraph S5.3.3 
to clarify that when an ESC system uses a two-part telltale, the 
malfunction telltale need not illuminate if the ``Off'' telltale is 
illuminated. We are revising S5.3.3 accordingly.
    However, we are denying the request to add a footnote to Table 1 of 
FMVSS No. 101 stating that a two-part ESC Off telltale is acceptable if 
the parts are simply configured as described. We do not believe that 
further clarification is necessary beyond what is already provided 
here.
    Additionally, we are denying Porsche's request to add a footnote to 
Table 1 stating that the ``ESC Off'' telltale is mandatory only when 
the system is manually disabled by the driver. S5.4.3 of FMVSS No. 126 
requires that the ESC Off telltale indicate the status of the ESC 
system when certain controls other than the manual ESC Off control have 
the ancillary effect of turning ESC off. The suggested footnote would 
conflict with this requirement.
2. Inclusion of ESC-Related Systems in ESC Malfunction Telltale 
Operational Requirements
    In the preamble to the ESC final rule, NHTSA agreed with commenters 
that a single malfunction telltale that relates generally to vehicle 
stability systems would be sufficiently informative for drivers, and 
would be effective in conveying the message that a malfunction has 
occurred which may require diagnosis and service by a repair facility. 
Thus, NHTSA included a footnote for Table 1 of FMVSS No. 101 stating, 
as regards the ESC malfunction telltale, that ``This symbol may also be 
used to indicate the malfunction of related systems/function including 
traction control, trailer stability assist, corner brake control, and 
other similar functions that use throttle and/or individual torque 
control to operate and share common components with the ESC system.''
    The Alliance/AIAM petitioned NHTSA to revise paragraphs S5.3.3 and 
S5.3.8 of FMVSS No. 126 to clarify that the ESC malfunction telltale 
may be illuminated to indicate a malfunction of related systems, and 
also may flash to indicate operation of a related system. Petitioners 
expressed concern that the omission of this clarification might create 
an inconsistency with FMVSS No. 101.
    Agency response: We are granting this petition in part. We agree 
that it would improve FMVSS No. 126's clarity to amend the regulatory 
text to specify that related systems may use the ESC malfunction 
telltale and that the ESC malfunction telltale may flash to indicate 
operation of a related system. Instead of revising S5.3.3 and S5.3.8 as 
suggested by the Alliance/AIAM petition, we are revising S5.3.3 
slightly, and are adding a new S5.3.10 to address these issues. S5.3.10 
will state:

    Manufacturers may use the ESC malfunction telltale in a steady 
burning mode to indicate malfunctions of ESC-related systems/
functions including traction control, trailer stability assist, 
corner brake control, and other similar functions that use throttle 
and/or individual wheel torque control to operate and share common 
components with the ESC system, and they may use the ESC malfunction 
telltale in a flashing mode to indicate operation of these ESC-
related systems.

We believe this addition will address the Alliance/AIAM's concerns.
3. Compliance Dates for Telltale Requirements
    The final rule allowed manufacturers greater lead time to 
standardize the presentation of ESC controls and displays, deferring 
many of these requirements until the end of the phase-in, i.e., 
September 1, 2011. This was because NHTSA wanted to achieve the safety 
benefits of equipping vehicles with ESC as quickly as possible. 
Although the agency perceived certain advantages to standardizing 
controls and displays, it was not practicable to implement those 
changes in keeping with the accelerated phase-in schedule. Thus, many 
of the provisions of the final rule concerning controls and displays 
contain the phrase ``as of September 1, 2011.'' \12\
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    \12\ These include paragraphs S5.3.1, S5.3.2, S5.3.4, S5.4.2, 
S5.5.2, and S5.5.6.
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    The Alliance/AIAM petitioned NHTSA to include the phrase ``as of 
September 1, 2011'' in paragraphs S5.3.3 and S5.4.3 as well, since 
those paragraphs also concern controls and displays. Petitioners stated 
that ``Requiring manufacturers to meet the provisions of S5.3.3 and 
S5.4.3 [in keeping with the phase-in] will preclude the accrual of 
credits and prevent manufacturers from meeting the accelerated phase-in 
schedule specified in the final rule.''
    The Alliance/AIAM petition also requested that NHTSA clarify that 
the changes made to FMVSS No. 101 by the ESC final rule would also be 
mandatory at the same time as the controls and displays requirements in 
FMVSS No. 126, by changing the mandatory compliance date for the FMVSS 
No. 101 provisions in the final rule to September 1, 2011.
    Agency response: The petition to add the compliance date to S5.3.3 
and S5.4.3 of FMVSS No. 126 is moot, because the change requested by 
the Alliance/AIAM has already been made in a correction notice 
published by NHTSA on June 22, 2007.\13\
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    \13\ See supra note 5.
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    We are granting the petition to add the compliance date to the 
provisions in question in FMVSS No. 101. As written, FMVSS No. 101 
could be read to prohibit controls and displays that FMVSS No. 126 
would allow prior to September 1, 2011. NHTSA did not intend this 
result. Thus, we are adding ``As of September 1, 2011'' to the 
provisions on ESC telltales and identifiers in S5.5.2, S5.5.5, and 
Table 1 of FMVSS No. 101.

[[Page 54530]]

B. Multi-Function ESC Controls

    The Alliance/AIAM petitioned for clarification of paragraphs S5.4.2 
and S5.4.3 regarding a control switch or button that combines several 
functions, which we will call a ``multi-function'' control for 
simplicity.\14\ For background, paragraph S5.4.2 requires that an ESC 
control whose only purpose is to disable the ESC system or place it in 
a mode in which it no longer satisfies the performance requirements 
\15\ be labeled either with the ESC symbol plus the word ``Off'' or the 
phrase ``ESC Off.'' The ``ESC Off'' telltale must also illuminate when 
ESC is in a state in which it no longer satisfies the performance 
requirements. Paragraph S5.4.3 creates an exception for a control 
primarily for another function, such as a four-wheel drive low-range 
transfer case, that does not specifically control the ESC system 
directly, but has the ancillary effect of turning off ESC in low range. 
Such a control need not be labeled an ``ESC Off'' control, but the 
``ESC Off'' telltale must still illuminate if ESC is put in a state in 
which it no longer satisfies the performance requirements.
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    \14\ This question was also raised in a request for 
interpretation from Mr. Brian Latouf of General Motors North 
America, which the agency answered on August 29, 2007 (``the GM 
request for interpretation''.
    \15\ Of paragraphs S5.2.1, S5.2.2, and S5.2.3.
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    The Alliance/AIAM offered the example of a multi-function control 
that could be used to turn ESC off or on, but could also be used to 
turn traction control off and to select an ESC ``performance mode.'' 
Because such a control could be seen as neither a control whose only 
purpose is to disable ESC, nor a control for another system with an 
ancillary effect, petitioners requested that the agency clarify that 
multi-function controls like the one described are not prohibited by 
FMVSS No. 126. Figure 1 below shows a rotary multi-function control 
(this example was provided in the petition).
[GRAPHIC] [TIFF OMITTED] TR22SE08.005

    Agency response: We are granting the petition to clarify S5.4.3, 
although we note that this question was already answered in the 
affirmative in the agency's response to the GM request for 
interpretation. FMVSS No. 126 does not prohibit multi-function ESC 
controls that combine the control whose only purpose is to disable the 
ESC system with controls used for other purposes. Paragraph S5.4 
specifically allows controls whose sole purpose is to disable ESC and 
establishes various requirements for them. The only reason that the 
standard distinguishes between these controls used only for disabling 
ESC from those used to control systems with an ancillary effect on ESC 
is to express the labeling requirements for the control symbols. The 
multi-function control example presented by the petition combines 
several controls in a single piece of hardware: one control whose only 
purpose is to disable ESC, one unregulated control for the traction 
control system, and another control that places the ESC system in an 
intermediate ``sport'' or ``performance'' mode.''
    In the rotary multi-function control example of Figure 1, the 
function within the control that disables ESC, because its only purpose 
is to disable ESC, would be required to be identified using the symbol 
or text specified in FMVSS No. 101 for ``ESC Off'' (effective September 
1, 2011) on or adjacent to that part of the control. We would not 
consider the precise example given by the Alliance/AIAM petition as 
satisfying FMVSS No. 101's requirement that the ``ESC Off'' label 
(``identifier'') be adjacent to the control it identifies, because the 
telltale lamp is located between the two.\16\ However, this problem 
could be solved by moving the lamp to the other side of the label.
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    \16\ FMVSS No. 101, S4 Definitions, defines ``Adjacent'' as 
``with respect to a control, telltale or indicator, and its 
identifier * * * (a) The identifier is in close proximity to the 
control, telltale or indicator; and (b) No other control, telltale, 
indicator, identifier or source of illumination appears between the 
identifier and the telltale, indicator, or control that the 
identifier identifies.''
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    FMVSS No. 126 does not specify requirements for the ``TC off'' 
function in the example, nor for the ``ESC Performance mode'' function, 
unless that function within the control places the ESC system in a mode 
in which it no longer satisfies the standard's performance 
requirements. If it did, it would be considered an ``ESC Off'' control 
(because it is a control whose purpose is to place the ESC system in a 
mode in which it no longer satisfies the performance requirements) and 
would also have to be labeled accordingly.
    The agency notes that in analyzing the applicability of the 
labeling requirement to the rotary multi-function control identified by 
the petition, we additionally considered other types of multi-function 
controls. For example, we considered toggle buttons which must be 
pressed repeatedly in order to cycle through multiple functions 
(including ESC Off), as well as controls used to navigate through 
multiple functions (including ESC Off) displayed in an information 
center. Just as for rotary multi-function controls, these other multi-
function controls must be labeled with ``ESC Off'' if they contain a 
function whose only purpose is to disable ESC or place it in a mode in 
which it no longer satisfies the performance requirements. NHTSA 
reiterates that ESC Off controls, regardless of whether they are 
contained within a multi-function control, must be labeled with ``ESC 
Off.'' We believe that this is necessary for the safety of the driver, 
and to discourage the driver from turning ESC off unless it is 
absolutely necessary. Unlike rotary controls, however, with a toggle 
button or a single button or switch for an information center, there is 
no obvious location for the ``ESC Off'' label. In these situations, we 
nevertheless require the control to be labeled with ``ESC Off,'' even 
if it also contains additional labels that the manufacturer believes 
are necessary to identify the other functions it contains.

[[Page 54531]]

    The Alliance/AIAM also petitioned NHTSA to remove the word ``only'' 
from S5.4 and S5.4.2 of the regulatory text in order to allow multi-
function controls. The agency is denying this aspect of the petition. 
S5.4 and S5.4.2 simply permit ESC Off controls and require them to be 
labeled with ``ESC Off.'' Paragraph S5.4 has been amended to state that 
``ESC Off'' controls may be included in multi-function controls. 
Therefore, we do not believe that removing the word ``only'' from the 
regulatory text is necessary.

C. ``ESC Off'' Control Labeling

    As explained in this response to petitions and in the final rule, 
paragraph S5.4.2 requires that an ESC control whose only purpose is to 
disable the ESC system or place it in a mode in which it no longer 
satisfies the performance requirements, be labeled with either the ESC 
symbol plus the word ``Off'' or the phrase ``ESC Off.'' NHTSA believes 
that labeling these controls with ``ESC Off'' is necessary to ensure 
that drivers clearly understand that they may lose the safety benefits 
of ESC by using this control.
    The Alliance/AIAM petitioned NHTSA to change the control labeling 
requirements in the final rule to require simply the label ``ESC'' 
rather than the label ``ESC Off.'' Petitioners argued that requiring 
the word ``Off'' on even dedicated controls ``will result in customer 
confusion and dissatisfaction.'' Petitioners also asserted that 
``labeling a control with 'Off' is unprecedented and inconsistent with 
the way that similar controls are handled in various Federal Motor 
Vehicle Safety Standards.'' Therefore, they requested that the relevant 
provisions and table sections in FMVSS No. 101 and FMVSS No. 126 be 
revised to make the current ESC malfunction symbol (that is, the ESC 
symbol alone or the letters ``ESC'' alone) also the identifier for a 
control to be called the ``ESC control'' that could turn ESC off as one 
of its functions. The changes would retain the current ESC Off symbol 
as an identifier for the ``ESC Off'' telltale, but not for the control.
    Agency response: We are denying this petition, because as expressed 
repeatedly, we believe that labeling a control that disables ESC with 
``ESC Off'' is beneficial for safety and for driver comprehension. The 
final rule permitted ESC to be turned off by the driver only because 
there are rare circumstances in which turning ESC off could be 
advantageous. It did not require manufacturers to include an ESC Off 
control. NHTSA's primary concern in the final rule was to minimize the 
possibility of a driver turning ESC off accidentally, or being 
otherwise unsure of the ESC system's status. The control was required 
to be labeled ``ESC Off'' to discourage drivers from touching the 
control unless they truly wanted to disable the system. NHTSA remains 
concerned that using simply the ESC symbol or letters ``ESC'' for these 
controls could lead drivers to think they had to use the control to 
select ESC operation, when they would almost always be safer not 
touching the control at all.
    The Alliance/AIAM petition offered no new evidence that the current 
requirements for labeling the ESC Off control are in any way more 
confusing or less effective in fulfilling the agency's goal of 
discouraging drivers from casually or unintentionally disabling ESC 
than their suggested alternatives. Consequently, we are denying this 
petition.

D. Disconnection of the Optional ``ESC Off'' Control

    In the final rule, NHTSA stated that although it would consider a 
disconnection of the ``ESC Off'' control to constitute a malfunction 
suitable for simulation under the standard, because it directly impacts 
ESC operability, until the end of the phase-in period we would allow 
manufacturers to not illuminate the ESC malfunction telltale for 
disconnection of the ``ESC Off'' control.\17\ At the time, this was 
permitted in order to accommodate the current lack of standardization 
of ESC controls and displays, which would be resolved by the end of the 
phase-in period. The Alliance/AIAM petitioned NHTSA to clarify that 
there is no requirement to illuminate the malfunction telltale when the 
ESC control is disconnected, and in doing so, to remove the exclusion 
in S5.3.9 that states that ``a disconnection of the ``ESC Off'' control 
need not illuminate the ESC malfunction telltale.'' S5.3.9 currently 
reads as follows:
---------------------------------------------------------------------------

    \17\ 72 FR 17271 (Apr. 6, 2007).

    S5.3.9 Prior to September 1, 2011, a disconnection of the power 
to the ESC electronic control unit may be indicated by the ABS 
malfunction telltale instead of the ESC malfunction telltale and a 
disconnection of the ``ESC Off'' control need not illuminate the ESC 
---------------------------------------------------------------------------
malfunction telltale.

    The Alliance/AIAM argued that because S5.3.9 provides an exception 
for vehicles built before September 1, 2011, a requirement is implied 
after that date. Petitioners further argued that it is neither 
necessary nor appropriate to require the malfunction telltale to 
illuminate when the disable control is disconnected, because as a 
practical matter, a fault in the optional ESC Off control will not 
affect the ability of the ESC system to function. Thus, the Alliance/
AIAM requested that NHTSA remove the last clause of S5.3.9, and simply 
clarify in the preamble that a disconnection of the ``ESC Off'' control 
need not illuminate the ESC malfunction telltale.
    Agency response: We are granting this petition, because it appears 
that no vehicles currently have the means to detect an ESC Off switch 
disconnection, and because upon further consideration we believe that 
an identical safety level will be maintained. Generally speaking, when 
an ESC Off switch becomes disconnected, the result will be equivalent 
to having no ESC Off control at all--which would frequently be 
preferable from a safety perspective. The driver would only be aware of 
the disconnection if he or she attempted to use the control to disable 
ESC and the ``ESC Off'' telltale did not illuminate. The only 
circumstance that NHTSA can imagine in which a disconnection of the ESC 
Off control would be different than simply not having an ESC Off 
control would be if the control became disconnected after it had been 
used to turn off the system, which would affect the control signal to 
turn ESC back on and could thus conceivably create a safety risk. We 
believe, however, that this would be a very rare occurrence. Moreover, 
if the switch is disconnected while the ESC is off, the driver retains 
the warning of the status indicator, and ESC will be automatically 
restored as soon as the vehicle is restarted, because that function is 
controlled by the ESC's electronic control unit, which is not affected 
by the switch's disconnection.
    Thus, we clarify that ESC Off switch disconnections that do not 
affect ESC operation other than in the narrow circumstance described 
above would not be considered an ESC system malfunction severe enough 
for a telltale warning. We are revising paragraph S5.3.9 to remove the 
text in question.

E. Automatic Return of ESC System to ``On'' Mode for Each Ignition 
Cycle

    The final rule included an ignition cycle default requirement in 
paragraph S5.4.1, which required the ESC system to return to a mode 
that satisfied the equipment and performance requirements ``at the 
initiation of each new ignition cycle, regardless of what mode the 
driver had previously selected.'' If the system had multiple modes that 
satisfied the requirements, ``the default mode must be the mode that 
satisfies the performance requirements * * * by the greatest

[[Page 54532]]

margin.'' However, the final rule included an exception for vehicles 
from returning to the default mode if the mode previously selected by 
the driver ``is specifically for enhanced traction during low-speed, 
off-road driving and is entered by the driver using a mechanical 
control that cannot be automatically reset electrically.'' This 
exception was included in response to manufacturer comments that 
certain low-range, speed-limited 4-wheel drive modes were accessed via 
use of a mechanical lever, and there was no way to move the lever back 
automatically to return to the default mode at the start of each new 
ignition cycle. Additionally, the agency agreed that there could be a 
safety risk if, for example, a vehicle in 4-wheel drive driving up a 
steep hill suddenly stalled and had to be restarted, but returned to 2-
wheel drive because of the ignition cycle default requirement which 
required that the default mode be the one that satisfied the 
performance requirements by the greatest margin.
    The Alliance/AIAM petitioned NHTSA to change the word 
``mechanical'' in S5.4.1 to ``manual,'' essentially broadening the 
exclusion from the key cycle automatic ESC reactivation requirement for 
low-speed off-road modes that are selected by the driver using an 
electronic control. Petitioners argued that the safety concerns (i.e., 
preventing ESC from reactivating when it could be harmful, as when the 
vehicle is stuck in snow or negotiating rugged or steep terrain) 
applied the same for electrically-selected modes as for mechanically-
selected modes. However, petitioners subsequently submitted revised 
recommendations on this issue, focusing not only on the ``mechanical'' 
versus ``manual'' distinction, but also more broadly on how the 
ignition cycle default requirement should be applied for maximum safety 
when a vehicle offers multiple drive configuration options (like 2-
wheel drive, low-range 4-wheel drive, high-range 4-wheel drive with 
locked center differential, etc.). The discussion below addresses the 
various aspects of this issue.
    Broader exclusion of low-speed off-road modes from ignition cycle 
reactivation requirement:
    The Alliance/AIAM petitioned for a broader exception in S5.4.1 for 
all low-speed off-road modes, including those induced by non-mechanical 
driver-selectable controls like touch screens or push buttons. 
Petitioners argued that safety concerns are still relevant for these 
modes just as they are for the agency's current exclusion for 
mechanically-selected low-speed off-road modes. For example, whether a 
vehicle is placed in an alternate mode mechanically or by pressing a 
button on a touch screen, if the mode is used for driving up steep 
hills or navigating rough terrain, requiring it to revert to a mode 
inappropriate for those conditions if the vehicle stalls and must be 
restarted could create hazards for the driver.
    Agency response: We are granting this petition by tying S5.4.1's 
exception directly to the low-range configuration of 4WD vehicles 
actually designed for off-road capability, and defining 4WD low-range 
configuration to specify minimum low-range gear reduction to assure 
that the vehicle is limited to low-speed operation. NHTSA agrees that 
the safety issue raised by petitioners is valid, and believes that the 
safety concerns associated with allowing a vehicle to remain in low-
range 4WD upon restart should be minimized, since the vehicle will be 
limited to low speeds.
    ``Opposition'' of S5.2's two requirements of stability and 
responsiveness and ``by the greatest margin'' requirement for different 
drive configurations:
    The Alliance/AIAM petitioned to revise the exception language of 
S5.4.1 that provides that the default mode to which ESC must return 
must be ``the mode that satisfies the performance requirements of S5.2 
by the greatest margin.'' Petitioners argued that S5.2's two 
requirements of stability and responsiveness ``are often in opposition 
with each other.'' This is because increasing ESC intervention may 
increase the compliance margin for the stability requirement, but also 
reduce the margin for responsiveness, while the opposite will happen 
when ESC intervention is decreased, as in the various ``ESC performance 
modes'' that petitioners offer on their vehicles. Petitioners had no 
specific request on this issue, but appear to have incorporated this 
concern into other requests for changes to regulatory text.
    Also on the issue of the S5.2 reference in S5.4.1, the Alliance/
AIAM requested that the agency not require vehicles in high-range 4WD 
locked-differential modes to return automatically to the ESC mode with 
the greatest margin of compliance with S5.2's requirements. Petitioners 
argued that this requirement complicates compliance, and thus potential 
credit earnings, for vehicles with a high-range 4WD mode with a locked 
center differential, because ESC algorithms must be adjusted to 
accommodate those modes, so that they intervene differently in those 
contexts. Thus, even if the ESC system could meet S5.2 in these modes, 
it might not meet it by the greatest margin as required by S5.4.1, so 
it would have to be shifted back to 2WD.
    Petitioners argued that this result is a problem for several 
reasons. First, none of the systems on vehicles with high-range 4WD 
modes with locked center differential are currently capable of 
automatically switching back to 2WD mode (and unlocking the center 
differential) with the ignition cycle alone. Second, as for all 
restarts in a new drive configuration mode, it can conceivably create a 
safety hazard or severe inconvenience for the driver--a vehicle in 4WD 
may stall in mud or snow and end up deeply dug in before the driver 
realizes that it restarted in 2WD. And third, as addressed in the final 
rule, vehicles that use mechanical controls to access the high-range 
4WD mode with locked center differential have no practical way of 
reverting automatically to 2WD at a new ignition cycle.
    Agency response: We are granting these requests by revising 
S5.4.1's default mode requirement to refer to ESC modes within the same 
drive configuration mode, and by removing the ``by the greatest 
margin'' requirement. Unlike in the case of low-range 4WD with a locked 
center differential, ESC continues to operate in the corresponding 
high-range mode. However, because 4WD vehicles are not designed to be 
driven on dry pavement with a locked center differential,\18\ there is 
little information about their results in the FMVSS No. 126 performance 
test, which is conducted on dry pavement. It is possible that vehicles 
may pass the test in 4WD with a locked center differential, but the 
test is much more representative of what the vehicle encounters when 
operated in 2WD mode. If the vehicle does not pass the test in 4WD with 
a locked center differential, it would be required to

[[Page 54533]]

revert automatically to 2WD mode at a new ignition cycle.
---------------------------------------------------------------------------

    \18\ By way of background, high-range 4WD with locked center 
differential is designed for driving in snow or on unpaved roads, 
where there is no particular need to drive slowly, so it is not 
speed-limited by low gear ratios. ``Locked center differential'' 
means that the drive gears at the front and rear axles are locked 
together, so they do not move independently like they ordinarily 
would. With a locked center differential, tires that would have no 
traction (when, for example, passing over an ice patch) are able to 
``slip'' due to the locked axles and continue moving, so the vehicle 
avoids getting stuck. Tire slippage can be helpful when a driver is 
negotiating slippery surfaces like packed snow, but it creates large 
forces and causes rapid tire wear when the tires are forced to slip 
on dry pavement, because the axles are essentially fighting one 
another. Thus, vehicles are capable of driving on regular dry 
pavement in high-range 4WD with locked center differential, but the 
driver would probably not want to remain in that mode for long.
---------------------------------------------------------------------------

    However, NHTSA realizes that this result would not be beneficial in 
some of the situations described by petitioners, such as when the 
vehicle is operating in loose sand or snow and could get dug in by 
restarting in 2WD. Additionally, we realize that vehicles with 
mechanical controls cannot automatically revert to another mode when 
the ignition is cycled. It was not the agency's intent to require these 
results. Moreover, as a practical matter, the ESC performance test is 
conducted with the vehicle coasting, so a locked center differential 
will cause considerable longitudinal wheel slip and slow the vehicle 
quickly during the test, aiding its stability. For these reasons, NHTSA 
is revising S5.4.1's default mode requirement to refer to ESC modes 
within the same drive configuration mode.
    However, because ESC can remain operative in high-range 4WD with 
locked center differential, and may be able to meet FMVSS No. 126's 
stability performance requirements, we are specifying that a vehicle in 
high-range 4WD with locked center differential need not revert to 2WD 
with the next ignition cycle if it can meet the stability performance 
requirements of S5.2.1 and S5.2.2. As stated, locking the vehicle's 
center differential will likely result in increased understeer. This 
will have the inherent effect of improving lateral stability, but at 
the expense of some responsiveness degradation. However, in the driving 
situations appropriate for use of the high-range 4-wheel drive 
configuration with locked center differential mode (i.e., snow- or ice-
covered roads, or on unpaved roads), we believe the benefits of 
improved lateral stability outweigh the ancillary effect of reduced 
responsiveness. Therefore, for vehicles placed in a high-range 4WD with 
locked center differential mode, we are only requiring the ESC system 
to revert at each ignition cycle to a mode that can meet the stability 
performance requirements. We believe that this solution resolves 
petitioners' concerns about vehicles not being able to meet both 
stability and responsiveness requirements in high-range 4WD with locked 
center differential.
    Additionally, we are removing the sentence at the end of S5.4.1 
that includes the ``by the greatest margin'' language, and are instead 
specifying that the default mode must be the ``manufacturer's 
original'' default mode. The ``by the greatest margin'' language was 
originally included in FMVSS No. 126 to ensure that the ignition cycle 
default mode was always the mode that provided the maximum level of 
safety, particularly if the ESC system included modes that were more 
``sporty'' and had a lower compliance margin, even if they met the 
performance requirements. However, upon further consideration, the 
agency believes it is highly unlikely that manufacturers would choose 
to offer ESC systems with default modes that were not the modes with 
the highest compliance margins. Therefore, we are simply requiring that 
vehicles return to the manufacturer's original default mode at the next 
ignition cycle. By ``manufacturer's original default mode,'' the agency 
means the basic ESC mode for the drive configuration, that is not a 
driver-selectable mode, that meets the final rule's performance 
requirements (or in the case of high-range 4WD with locked center 
differential, that meets the stability performance requirements).
    Request to allow technical documentation in lieu of meeting 
performance requirements:
    In their revised recommendations the Alliance/AIAM also argued that 
ESC modes induced by selecting high-range 4WD with locked center 
differential should not be required to satisfy S5.1 and S5.2 at the 
next ignition cycle as called for by S5.4.1. Petitioners requested that 
NHTSA instead require manufacturers to document, per the ``ESC System 
Technical Documentation'' provision of S5.6, that a control algorithm 
appropriate to high-range 4WD operation with a locked center 
differential is operational above 20 km/h in that drive configuration. 
With such documentation, the vehicle would not be required to change 
ESC modes or drive configuration at the initiation of a new ignition 
cycle.
    Agency response: We are denying this request. The situation 
presented by high-range 4WD with locked center differential is not 
suited to a documentation solution in the way that understeer 
mitigation is, which is what S5.6 was intended to address. Unlike 
understeer mitigation, it is possible to perform the test established 
by the standard even with the vehicle in high-range 4WD with locked 
center differential, and the test procedure should still be useful to 
demonstrate objectively that ESC remains functional in this drive 
configuration without the need to rely on documentation, as discussed 
above. The agency notes that a docket submission by Chrysler on 
September 26, 2007 supports the idea that ESC modes available with a 
locked center differential should be expected to satisfy the stability 
criteria (S5.2.1 and S5.2.2) of the ESC test used in FMVSS No. 126.\19\
---------------------------------------------------------------------------

    \19\ Docket No. NHTSA-2007-27662-12.
---------------------------------------------------------------------------

    We do not expect that vehicles tested with a locked center 
differential will meet the responsiveness criterion (S5.2.3) in a 
similar manner. However, responsiveness on a high coefficient of 
friction surface in a mode with the center differential locked is not 
relevant to evaluating the operation of ESC. Any lack of responsiveness 
in the test would not be the result of ESC operation, but rather the 
consequence of the front and rear drive axles creating high opposing 
forces, which cannot be resolved by tire slippage on dry pavement the 
way they would be on a surface like packed snow. As discussed above, 
the agency believes that in the case of vehicles in high-range 4WD with 
locked center differential, which are used primarily for safe handling 
on slippery surfaces like packed snow and dirt, vehicle stability is a 
more important property to demonstrate than vehicle responsiveness. 
Thus, manufacturers would have no obligation to ensure that vehicles in 
this drive configuration could meet S5.2.3.
    Whether the ``ESC Off'' indicator must be illuminated for driver 
selection of alternate operating modes:
    Finally, on the subject of driver-selectable operating modes, the 
Alliance/AIAM requested that NHTSA remove the requirement in S5.4.3 
that the ``ESC Off'' indicator be illuminated whenever a driver-
selectable operating mode renders the vehicle incapable of meeting the 
performance requirements of S5.2. Petitioners expressed concern that, 
if putting the vehicle in 4WD illuminates the ESC Off telltale, drivers 
might be discouraged from using 4WD because they might think that ESC 
is not working even though it has been optimized for that mode, or 
might seek unnecessary vehicle service for what appears to be a 
malfunction in their ESC system.
    Agency response: This issue is addressed by the agency's revision 
of S5.4.1 to require vehicles in particular 4WD modes to meet only the 
stability performance requirements of S5.2.1 and S5.2.2 and not the 
responsiveness requirement of S5.2.3 as well. If the ESC mode for a 
high-range 4WD with locked center differential drive configuration is 
capable of satisfying the stability criteria, it should not be 
considered as turning ESC off. Thus, there would be no reason to 
illuminate the ESC Off telltale. NHTSA is revising S5.4.4 and S5.5.4 to 
clarify this point.
    The table below summarizes the ignition cycle default requirements 
for

[[Page 54534]]

manually-activated ESC modes in different drive configurations and the 
required ESC Off telltale response:

                  Sample of Ignition Cycle Default Requirements of S5.4.1 With Telltale Status Requirements (List Is Not All-Inclusive)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Meets stability &
        Drive configuration                  Mode              responsiveness       ``Off  Telltale''       ESC default setting       ``Off  Telltale''
                                                                requirements              status              (ignition cycle)             status
--------------------------------------------------------------------------------------------------------------------------------------------------------
2WD (3 selections avail.).........  2WD..................  yes..................  off..................  2WD default meets           off.
                                                                                                          stability and
                                                                                                          responsiveness
                                                                                                          requirements.
                                    Performance 1........   yes.................   off.................   2WD default meets          off.
                                                                                                          stability and
                                                                                                          responsiveness
                                                                                                          requirements.
                                    Performance 2........   no..................   on..................   2WD default meets         off.
                                                                                                          stability and
                                                                                                          responsiveness
                                                                                                          requirements.
AWD/4WD Auto (1 selection avail.).  AWD/4WD Auto.........  no (neither).........  on...................  Default to some mode that  off.
                                                                                                          meets stability and
                                                                                                          responsiveness
                                                                                                          requirements.
                                    AWD/4WD Auto.........   no (stability--yes)    on..................   Default to some mode      off.
                                                            (responsiveness--no).                         that meets stability and
                                                                                                          responsiveness
                                                                                                          requirements.
                                    AWD/4WD Auto.........   yes.................   off.................   Default to some mode      off.
                                                                                                          that meets stability and
                                                                                                          responsiveness
                                                                                                          requirements.
4WD Hi Locked (1 selection avail.)  Locked...............  no (neither).........  on...................  Default to some mode that   off.
                                                                                                          meets stability
                                                                                                          requirements.
                                    Locked...............   no (stability--yes)   off..................  Default to some mode that   off.
                                                            (responsiveness--no).                         meets stability
                                                                                                          requirements.
                                    Locked...............  yes (both)...........   off.................  Default to some mode that   off.
                                                                                                          meets stability
                                                                                                          requirements.
4WD Low...........................  Low..................  no...................  on...................  Normal low...............  on.
Any Above.........................  ``ESC OFF'' Control    no...................  on...................  Default to applicable       off.
                                     activated.                                                           mode within existing
                                                                                                          drive configuration that
                                                                                                          meets appropriate
                                                                                                          performance requirements.
--------------------------------------------------------------------------------------------------------------------------------------------------------

F. Low-Speed Threshold for ESC Operation

    The final rule, in both the paragraph S4 definition of an ESC 
system and in paragraph S5.1.2 as part of the equipment requirements, 
requires ESC to operate at all speeds above 15 km/h (9.3 mph). NHTSA 
included a low-speed threshold for ESC operation as a result of 
comments to the NPRM. 15 km/h (9.3 mph) was chosen largely because that 
speed was the typical threshold for ABS operation, and ABS shares a 
number of components with ESC.\20\
---------------------------------------------------------------------------

    \20\ Id., at 17264.
---------------------------------------------------------------------------

    The Alliance and AIAM petitioned the agency to remove the low-speed 
threshold in the ESC system definition of paragraph S4, and to allow 
the manufacturer to determine the low-speed threshold and 
initialization period and conditions until the end of the phase-in 
period in paragraph S5.1.2. The Alliance/AIAM argued that ``Many 
current vehicles have a design cut-off threshold speed higher than the 
15 km/h (9.3 mph) specified in FMVSS 126,'' and that the different 
initialization periods required by different ESC systems may result in 
some systems not working until the vehicle has reached 32 km/h (20 
mph).\21\ Petitioners further argued that the 15 km/h (9.3 mph) low-
speed threshold would interfere with manufacturers' ability to accrue 
carry-forward and phase-in credits.\22\
---------------------------------------------------------------------------

    \21\ Alliance petition at 5.
    \22\ Id. at 6.
---------------------------------------------------------------------------

    In a supplemental document to its petition for reconsideration, the 
Alliance/AIAM requested a specific low-speed threshold of 20 km/h (12.4 
mph), but also that the agency still allow the manufacturer to 
determine the initialization period and conditions before the end of 
the phase-in period in S5.1.2.\23\ The petitioners stated that they had 
conducted additional research, and determined that their ``member 
vehicles'' could manage this revised low-speed threshold 
recommendation.
---------------------------------------------------------------------------

    \23\ Docket No. NHTSA-2007-27662-10, at 8.
---------------------------------------------------------------------------

    Agency response: We are granting this petition in part, although we 
are not adopting the exact language offered by the Alliance/AIAM. 
Regarding the low-speed threshold, the original proposed language of S4 
as contained in the NPRM stated that ESC must be operational ``over the 
full speed range of the vehicle (except below a low-speed threshold 
where loss of control is unlikely).'' As stated above, NHTSA included a 
specific speed designation for the low-speed threshold in the final 
rule in response to comments, but our goal has always been to avoid 
requiring ESC to operate at speeds below which loss of control is not a 
significant concern. NHTSA agrees that a low-speed threshold of 20 km/h 
(12.4 mph), consistent with the apparent capabilities of most of the 
existing ESC-equipped fleet, constitutes a limit for ESC operation 
below which loss of control is unlikely. Thus, the low-speed threshold 
is revised accordingly in S4 and S5.1.2 of the regulatory text.
    Additionally, the Alliance/AIAM petition requested that NHTSA allow 
manufacturers to determine their own initialization periods until the 
end of the phase-in period. NHTSA is denying this petition because we 
are revising S4 and S5.1.2 to clarify that ESC need not be operational 
during system initialization. This point was already made in our letter 
of interpretation to GM, but we believe that this minor clarification 
should also be made to the regulatory text to avoid any further 
confusion.

G. Fault Detection and Cancellation Test Procedures

    The need of the ESC system to initialize affects provisions of 
FMVSS No. 126 in addition to the definition of ESC system in S4 and the 
description of the required equipment in S5.1.2. For example, if the 
system has not completed initialization and is not yet operational, it 
likely cannot detect malfunctions in the system--a problem which 
relates to the requirements for ESC malfunction telltales and for their 
testing. Paragraph S5.3 establishes the requirement for a malfunction 
telltale

[[Page 54535]]

for ESC systems and specifies a number of attributes for the telltale. 
Paragraph S7.10 of the standard sets forth a test procedure for the 
malfunction telltale, and S7.10.2 accounts for the need for the vehicle 
to be driven for up to two minutes to allow the ESC system to 
initialize and conduct diagnostics in order for it to be able to detect 
a malfunction.
    The Alliance/AIAM petition asked the agency to clarify that the 
initialization procedure necessary for the system to find a malfunction 
and illuminate the telltale (in S7.10.2) is also applied to the vehicle 
when the telltale is tested for extinguishment after the fault is 
corrected (S7.10.4).\24\ Petitioners further requested that the ESC 
malfunction telltale test procedure be referenced in S5.3 to assure 
that the test procedures are reflected in the ESC malfunction 
requirements section of the standard. Additionally, petitioners argued 
that most current ESC systems require a brake application in order to 
detect some ESC system malfunctions, and petitioned the agency to 
include a requirement for a brake application in the initialization 
procedure.
---------------------------------------------------------------------------

    \24\ This point was also answered in the GM letter of 
interpretation.
---------------------------------------------------------------------------

    Agency response: We are granting these requests. As discussed 
above, the agency did not intend to require ESC to operate when it is 
still initializing. For a system that needs to initialize before it can 
discover a malfunction and illuminate the malfunction telltale, like 
the majority of the ESC systems currently on the market, the system 
cannot discover that the malfunction is no longer present and 
extinguish the telltale without completing the same initialization 
procedure. Therefore, the agency is including the same initialization 
procedure in S7.10.4 as is already specified in S7.10.2. Similarly, to 
clarify that the vehicle must be initialized before testing begins, we 
are including the same initialization procedure in S6.3.1, as part of 
the test conditions. Additionally, after considering the petitions, we 
consider the inclusion of a brake application in the initialization 
procedure requirements to be a very minor amendment. We are revising 
the regulatory text to reflect these changes.
    In considering these requests, the agency also noted that S7.10.3 
of the ESC malfunction detection procedure requires that the telltale 
illuminate immediately when the engine is restarted following an 
ignition cycle in which a malfunction was detected. In other words, the 
ESC system must hold the existence of a malfunction in memory, rather 
than rediscovering it with the new ignition cycle. Some ESC systems 
currently on the market must initialize before they can identify some 
specific types of malfunctions, which means that they are unable to 
hold the existence of a malfunction in memory. For these systems, we 
recognize that this requirement simply cannot be met, although it may 
be possible for other ESC systems that do not need to initialize to 
recognize a malfunction. In order to be consistent with the other 
provisions of S7.10, the agency is making S7.10.3 effective at the end 
of the phase-in, and will revise the regulatory text accordingly. 
However, we note that after the phase-in, all ESC systems must be able 
to hold malfunctions in memory and illuminate the malfunction telltale 
immediately upon engine restart if the malfunction still exists.

H. Effective Dates for Amended Procedures and Requirements

    The Alliance/AIAM petitioned that the revisions they requested to 
the final rule be made retroactive to June 5, 2007 (the effective date 
of the final rule), so that carry-forward credits for complying 
vehicles built after that date could be used by manufacturers in 
satisfying the phase-in schedule for that standard.
    Agency response: We are granting this petition, to the extent to 
which we are making the revisions requested in the petition. In the 
April 2007 final rule, NHTSA provided that manufacturers may earn 
credits for vehicles manufactured on or after June 5, 2007, that comply 
with the new ESC standard. In today's final rule, we are making a 
number of minor amendments to that standard, many of which are of a 
clarifying nature and none of which affect safety benefits.
    Given our decision in the April 2007 final rule to permit 
manufacturers to earn credits for complying vehicles manufactured on or 
after June 5, 2007 and given the minor nature of today's amendments, it 
is our position that manufacturers may earn credits for vehicles 
manufactured on or after that date if the vehicles comply with the 
standard as amended by today's rule. We believe it is sufficient to 
make that point in this preamble.
    We are making this final rule effective 30 days after publication. 
The amendments do not impose new requirements but instead provide 
clarification and additional flexibility in appropriate areas. We 
accordingly find good cause for making the rule effective in this 
timeframe.

I. Inclusion of Roll Stability Control in the Scope of the Final Rule

    AAJ petitioned NHTSA to reconsider its decision not to address the 
need for roll stability control in the final rule. It argued that the 
agency's statement in the final rule that ``There is currently an 
insufficient body of data to judge the efficacy of [these] systems'' 
\25\ was incorrect, because ``the agency may be able to obtain the 
appropriate information through its authority to institute a rulemaking 
or to issue a subpoena.'' \26\ It also argued that if NHTSA declines to 
reconsider the final ESC rule on this basis, ``the agency must 
establish a rulemaking to address RSC immediately,'' because doing so 
``would develop the statistics to demonstrate the efficacy of such 
systems.'' \27\
---------------------------------------------------------------------------

    \25\ 72 FR 17236, 17239 (Apr. 6, 2007).
    \26\ AAJ petition at 1, available at Docket No. NHTSA-2007-
27662, item 6.
    \27\ Id. at 2.
---------------------------------------------------------------------------

    Agency response: We are denying this petition. While we may 
consider establishing requirements for roll stability control in the 
future, we reiterate that insufficient data currently exists for the 
agency to establish such requirements as part of FMVSS No. 126, as we 
discussed at length in the final rule.\28\ In explaining the basis of 
our decision, we will first explain the difference between the yaw 
stability control that ESC produces and roll stability control, and 
then explain briefly why we did not include roll stability control as 
part of the ESC final rule.
---------------------------------------------------------------------------

    \28\ See 72 FR 17236 at 17253, 17258 (Apr. 6, 2007).
---------------------------------------------------------------------------

    ``Yaw stability control'' is the technical term for the action of 
ESC which keeps the vehicle pointed in the direction the driver is 
steering through the automatic reduction of engine power and automatic 
application of braking at individual wheels to turn the vehicle, in 
order to help drivers avoid imminent loss-of-control situations.\29\ 
``Roll stability control,'' in contrast, prevents vehicle tip-up by 
sensing the vehicle's body roll angle and applying a high brake force 
to the outside front wheel to straighten the vehicle's path and reduce 
lateral acceleration if the roll angle indicates probable tip-up. Put 
differently, yaw stability control is based on the vehicle's sensing 
loss of control on the horizontal plane, and roll stability control is 
based on the vehicle's sensing loss of control on the vertical plane, 
although both use brake forces at individual wheels to make the path 
correction. Additionally, yaw

[[Page 54536]]

stability control must be temporarily overridden to allow roll 
stability control to change the path of the vehicle to reduce lateral 
acceleration.
---------------------------------------------------------------------------

    \29\ The final rule contains a much more thorough description of 
how ESC uses yaw stability control. See id. at 17243-44 (Apr. 6, 
2007).
---------------------------------------------------------------------------

    NHTSA did not include requirements for roll stability control in 
the final rule for several reasons. First, roll stability control 
involved relatively new technology, and none of the vehicles examined 
in NHTSA's crash data study which proved the substantial safety 
benefits of yaw stability control also had roll stability control. We 
do not currently have sufficient information on the effectiveness of 
roll stability control as a safety technology to include it as part of 
this safety standard. Moreover, because roll stability control in 
theory functions by temporarily disabling yaw stability control, NHTSA 
cannot judge its overall effect without real-world crash data.
    Our highest priority is ensuring that the ESC systems required by 
FMVSS No. 126 are present on all vehicles as soon as possible. Just 
because the final rule did not include roll stability control as part 
of FMVSS No. 126, however, does not mean that the agency does not 
acknowledge that the technology may eventually demonstrate safety 
benefits. We stated in the final rule that ``The agency will track the 
rollover rate of vehicles equipped with roll stability control through 
analysis of State-generated crash data and evaluate its effectiveness 
once a sufficient sample size becomes available (i.e., approximately 
three to four years).'' \30\ Further, FMVSS No. 126 does not preclude 
manufacturers from equipping vehicles with roll stability control.
---------------------------------------------------------------------------

    \30\ 72 FR 17236, 17258 (Apr. 6, 2007).
---------------------------------------------------------------------------

    Finally, we are denying AAJ's request that ``the agency * * * 
establish a rulemaking to address [roll stability control] 
immediately'' if it denies the petition for reconsideration. As 
discussed above, NHTSA will continue monitoring roll stability control 
as a safety technology. We are undertaking our own research on RSC, and 
are collecting comparative crash data on RSC-equipped vehicles from the 
states. We will consider initiating rulemaking as we gather more 
information regarding its practicability and the safety benefits that 
it provides. As the final rule stated,

    * * * because our data study showed yaw stability control 
reducing rollovers of SUVs by 84% by reducing and mitigating road 
departures, and because on-road untripped rollovers are much less 
common events, the target population of crashes that roll stability 
control could possibly prevent may be very small. If and when roll 
stability control can be shown to be cost-effective, then it could 
be a candidate for inclusion in the standard in subsequent 
rulemaking.\31\
---------------------------------------------------------------------------

    \31\ 72 FR 17236, 17258 (Apr. 6, 2007).

AAJ provided no additional facts or information in its petition for 
reconsideration/rulemaking that contributes to the agency's 
understanding of whether a roll stability control safety standard is 
necessary or helpful at this time, or whether requiring manufacturers 
to provide the information on roll stability control that AAJ suggests 
would, in fact, be necessary or helpful. Therefore, we are denying its 
request.

J. NHTSA's Discussion of Implied Preemption

    AAJ objected to the agency's general statement in the final rule 
preamble that, in Geier v. American Honda Motor Co., the Supreme Court 
recognized the possibility that state tort law can create an obstacle 
to a NHTSA safety standard and could therefore be impliedly preempted. 
AAJ interpreted that statement as a claim by the agency that the ESC 
rule itself impliedly preempts state tort law and requested that the 
agency eliminate that statement. (Since the agency cannot ``eliminate'' 
a discussion in the preamble of an already published final rule, we 
assume that AAJ is asking that the agency ``disavow'' the discussion.) 
AAJ argued that ``Geier is an unusual, fact-driven case which cannot be 
used to establish preemption of state tort law for all NHTSA motor 
vehicle safety rules.'' Based on its view that the agency had made a 
claim of preemption, AAJ further argued that, under the Administrative 
Procedure Act, ``any claim of conflict preemption must be preceded by 
notice and comment as to whether a direct conflict exists between state 
law and the electronic stability control rule.''
    Agency response: The agency does not consider this portion of AAJ's 
submission to be a petition for reconsideration, as NHTSA's preemption 
discussion is not a rule.\32\ Accordingly, we are treating this portion 
as a simple request to disavow the discussion in the final rule 
preamble.
---------------------------------------------------------------------------

    \32\ See 49 CFR Sec.  553.35, ``Petitions for Reconsideration,'' 
paragraph (a), which states that ``Any interested person may 
petition the Administrator for reconsideration of any rule issued 
under this part. * * * The petition must contain a brief statement 
of the compliant and an explanation as to why compliance with the 
rule is not practicable, is unreasonable, or is not in the public 
interest.'' (Emphasis added.)
---------------------------------------------------------------------------

    We provided the general discussion of implied preemption and Geier 
in accordance with the directive of Executive Order 13132, Federalism, 
for agencies to analyze the federalism implications of their 
rulemakings. In that discussion, the agency explained that NHTSA's 
safety standards can preempt state laws in at least two ways: Either 
expressly, through the express preemption provision of the Vehicle 
Safety Act, or impliedly, if State requirements create a conflict and 
thus stand as an obstacle to the accomplishment and execution of a 
NHTSA safety standard.\33\ Per the Order, we considered the nature of 
the ESC standard and its objectives and whether there might be specific 
conflicts between the standard and anticipated State tort law. We did 
not detect any conflicts.\34\ Without a conflict, there is no implied 
preemption. However, we could not then, and cannot now, completely rule 
out the possibility that such a conflict might become apparent in the 
future through subsequent experience with the standard. Even if the 
agency had identified what it believed to be a conflict, the issue of 
whether there was a conflict and, if so, whether State tort law action 
would be impliedly preempted would ultimately be a matter for the 
courts to decide. For the aforementioned reasons, the agency declines 
to remove the Geier language from its discussion of preemption law.
---------------------------------------------------------------------------

    \33\ See the ``Federalism'' discussion at 72 FR 17300-01 (Apr. 
6, 2007).
    \34\ Id.
---------------------------------------------------------------------------

K. International Harmonization and the Global Technical Regulation for 
ESC

    The April 2007 final rule described NHTSA's intent to begin formal 
work to develop a global technical regulation (GTR) on ESC in that 
year. Over the course of several meetings of the United Nations' 
Economic Commission for Europe (UNECE) World Forum for the 
Harmonization of Vehicle Regulations (WP.29) during 2007 and 2008, the 
agency participated in successful efforts that culminated in the 
establishment of the ESC GTR under the 1998 Global Agreement.\35\ The 
U.S., as a Contracting Party of the 1998 Agreement that voted in favor 
of establishing this GTR, is obligated under the Agreement to initiate 
the process for adopting the provisions of the GTR.\36\ The issuance of 
this response to petitions for reconsideration fulfills the obligation 
of

[[Page 54537]]

the U.S. to initiate that process. The regulatory text of the April 
2007 final rule, as amended by this document, is consistent with that 
of the GTR.
---------------------------------------------------------------------------

    \35\ Although commonly referred to as the 1998 Global Agreement, 
this provision is more formally titled the ``1998 Agreement 
Concerning the Establishing of Global Technical Regulations for 
Wheeled Vehicles, Equipment and Parts which can be Fitted and/or be 
Used on Wheeled Vehicles.''
    \36\ While the 1998 Agreement obligates such Contracting Parties 
to initiate rulemaking within one year of the establishment of the 
GTR, it leaves the ultimate decision of whether to adopt the GTR 
into their domestic law to the parties themselves.
---------------------------------------------------------------------------

IV. Rulemaking Analyses and Notices

    This rule makes several minor changes to the regulatory text of 
FMVSS No. 126, and does not increase the regulatory burden of 
manufacturers. The agency has discussed the relevant requirements of 
the Vehicle Safety Act, Executive Order 12866, the Department of 
Transportation's regulatory policies and procedures, the Regulatory 
Flexibility Act, Executive Order 13132 (Federalism), Executive Order 
12988 (Civil Justice Reform), Executive Order 13045 (Protection of 
Children from Environmental Health and Safety Risks), the Paperwork 
Reduction Act, the National Technology Transfer and Advancement Act, 
the Unfunded Mandates Reform Act, and the National Environmental Policy 
Act in the April 2007 final rule cited above. Those discussions are not 
affected by these changes.

Privacy Act

    Please note that any one is able to search the electronic form of 
all documents received into any of our dockets by the name of the 
individual submitting the document (or signing the document, if 
submitted on behalf of an association, business, labor union, etc.). 
You may review DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (Volume 65, Number 70; Pages 
19477-78), or you may visit http://www.dot.gov/privacy.html.

V. Regulatory Text

List of Subjects in 49 CFR Parts 571 and 585

    Imports, Motor vehicle safety, Report and recordkeeping 
requirements, Tires.

0
In consideration of the foregoing, NHTSA is amending 49 CFR part 571 as 
follows:

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. The authority citation for part 571 continues to read as follows:

    Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.50.

0
2. In Section 571.101, revise S5.5.2, S5.5.5, and Table 1 to read as 
follows:

Sec.  571.101  Standard No. 101; Controls and displays.

* * * * *
    S5.5.2 The telltales for any brake system malfunction required by 
Table 1 to be red, air bag malfunction, low tire pressure, electronic 
stability control malfunction (as of September 1, 2011), passenger air 
bag off, high beam, turn signal, and seat belt must not be shown in the 
same common space.
* * * * *
    S5.5.5 In the case of the telltale for a brake system malfunction, 
air bag malfunction, side air bag malfunction, low tire pressure, 
electronic stability control malfunction (as of September 1, 2011), 
passenger air bag off, high beam, turn signal, or seat belt that is 
designed to display in a common space, that telltale must displace any 
other symbol or message in that common space while the underlying 
condition for the telltale's activation exists.
* * * * *
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0
3. In Section 571.126, revise S4, S5.1.2, S5.3, S5.3.3, S5.3.9, S5.4, 
S5.4.1, S5.4.2, S5.4.3, ,S5.5.1, S5.5.4, S6.3.1, S7.10.2, S7.10.3, and 
S7.10.4 to read as follows; add S5.3.10, S5.4.2, and S5.5.10 to read as 
follows; and redesignate S5.4.2 and S5.4.3 to S5.4.3 and S5.4.4, 
respectively to read as follows:

Sec.  571.126  Standard No. 126; Electronic stability control systems

* * * * *
    S4. Definitions.
    Ackerman Steer Angle means the angle whose tangent is the wheelbase 
divided by the radius of the turn at a very low speed.
    Drive configuration means the driver-selected, or default, 
condition for distributing power from the engine to the drive wheels 
(examples include, but are not limited to, 2-wheel drive, front-wheel 
drive, rear-wheel drive, all-wheel drive, 4-wheel drive high gear with 
locked differential, and 4-wheel drive low gear).
    Electronic stability control system or ESC system means a system 
that has all of the following attributes:
    (1) That augments vehicle directional stability by applying and 
adjusting the vehicle brake torques individually to induce a correcting 
yaw moment to a vehicle;
    (2) That is computer-controlled with the computer using a closed-
loop algorithm to limit vehicle oversteer and to limit vehicle 
understeer;
    (3) That has a means to determine the vehicle's yaw rate and to 
estimate its side slip or side slip derivative with respect to time;
    (4) That has a means to monitor driver steering inputs;
    (5) That has an algorithm to determine the need, and a means to 
modify engine torque, as necessary, to assist the driver in maintaining 
control of the vehicle; and
    (6) That is operational over the full speed range of the vehicle 
(except at vehicle speeds less than 20 km/h (12.4 mph), when being 
driven in reverse, or during system initialization).
    Lateral acceleration means the component of the vector acceleration 
of a point in the vehicle perpendicular to the vehicle's x-axis 
(longitudinal) and parallel to the road plane.
    Low-range four-wheel drive configuration means a drive 
configuration that has the effect of locking the drive gears at the 
front and rear axles together and providing an additional gear 
reduction between the engine speed and vehicle speed of at least 2.0.
    Mode means an ESC performance algorithm, whether driver-selected or 
not (examples include, but are not limited to, standard (default) mode, 
performance mode, snow or slippery road mode, or Off mode).
    Oversteer means a condition in which the vehicle's yaw rate is 
greater than the yaw rate that would occur at the vehicle's speed as a 
result of the Ackerman Steer Angle.
    Side slip or side slip angle means the arctangent of the lateral 
velocity of the center of gravity of the vehicle divided by the 
longitudinal velocity of the center of gravity.
    Understeer means a condition in which the vehicle's yaw rate is 
less than the yaw rate that would occur at the vehicle's speed as a 
result of the Ackerman Steer Angle.
    Yaw rate means the rate of change of the vehicle's heading angle 
measured in degrees/second of rotation about a vertical axis through 
the vehicle's center of gravity.
* * * * *
    S5.1.2 Is operational during all phases of driving including 
acceleration, coasting, and deceleration (including braking), except 
when the driver has disabled ESC, the vehicle speed is below 20 km/h 
(12.4 mph), the vehicle is being driven in reverse, or during system 
initialization
* * * * *
    S5.3 ESC Malfunction. The vehicle must be equipped with a telltale 
that provides a warning to the driver of the occurrence of one or more 
malfunctions that affect the generation or transmission of control or 
response signals in the vehicle's electronic stability control system. 
When tested according to S7.10, the ESC malfunction telltale:
* * * * *
    S5.3.3 As of September 1, 2011, except as provided in paragraphs 
S5.3.4, S5.3.5, S5.3.8, and S5.3.10, the ESC malfunction telltale must 
illuminate only when a malfunction(s) of the ESC system exists and must 
remain continuously illuminated under the conditions specified in S5.3 
for as long as the malfunction(s) exists (unless the ``ESC 
malfunction'' and ``ESC Off'' telltales are combined in a two-part 
telltale and the ``ESC Off'' telltale is illuminated), whenever the 
ignition locking system is in the ``On'' (``Run'') position; and
* * * * *
    S5.3.9 Prior to September 1, 2011, a disconnection of the power to 
the ESC electronic control unit may be indicated by the ABS malfunction 
telltale instead of the ESC malfunction telltale.
    S5.3.10 Manufacturers may use the ESC malfunction telltale in a 
steady-burning mode to indicate malfunctions of ESC-related systems and 
functions including traction control, trailer stability assist, corner 
brake control, and other similar functions that use throttle and/or 
individual wheel torque control to operate and share common components 
with the ESC system, and may use the ESC malfunction telltale in a 
flashing mode to indicate operation of these ESC-related systems.
    S5.4 ESC Off and Other System Controls. The manufacturer may 
include an ``ESC Off'' control whose only purpose is to place the ESC 
system in a mode or modes in which it will no longer satisfy the 
performance requirements of S5.2.1, S5.2.2, and S5.2.3. An ``ESC Off'' 
control may be combined with other controls in a multi-function 
control. Manufacturers may also provide controls for other systems that 
have an ancillary effect upon ESC operation. Controls of either kind 
that place the ESC system in a mode in which it will no longer satisfy 
the performance requirements of S5.2.1, S5.2.2, and S5.2.3 are 
permitted, provided that:
    S5.4.1 The vehicle's ESC system must always return to the 
manufacturer's original default ESC mode that satisfies the 
requirements of S5.1 and S5.2 at the initiation of each new ignition 
cycle, regardless of what ESC mode the driver had previously selected, 
unless (a) the vehicle is in a low-range four-wheel drive configuration 
selected by the driver on the previous ignition cycle that is designed 
for low-speed, off-road driving, or (b) the vehicle is in a four-wheel 
drive configuration selected by the driver on the previous ignition 
cycle that is designed for operation at higher speeds on snow-, sand-, 
or dirt-packed roads and that has the effect of locking the drive gears 
at the front and rear axles together, provided that the vehicle meets 
the stability performance requirements of S5.2.1 and S5.2.2 in this 
mode.
    S5.4.2 In addition to the requirements of S5.4.1, if the vehicle's 
ESC system has more than one ESC mode that satisfies the requirements 
of S5.1 and S5.2 within the drive configuration selected for the 
previous ignition cycle, the system must return to the manufacturer's 
original default ESC mode.
    S5.4.3 As of September 1, 2011, a control whose only purpose is to 
place the ESC system in a mode or modes in which it will no longer 
satisfy the performance requirements of S5.2.1, S5.2.2, and S5.2.3 must 
be identified by the symbol shown for ``ESC Off'' in Table 1 of 
Standard No. 101 (49 CFR

[[Page 54543]]

571.101), or the text, ``ESC Off'' as listed under ``Word(s) or 
Abbreviations'' in Table 1 of Standard No. 101 (49 CFR 571.101).
    S5.4.4 A control for another system that has the ancillary effect 
of placing the ESC system in a mode in which it no longer satisfies the 
performance requirements of S5.2.1, S5.2.2, and S5.2.3 need not be 
identified by the ``ESC Off'' identifiers in Table 1 of Standard No. 
101 (49 CFR 571.101), but the ESC status must be identified by the 
``ESC Off'' telltale in accordance with S5.5, as of September 1, 2011, 
except if the vehicle is in a 4-wheel drive high gear configuration 
that has the effect of locking the drive gears at the front and rear 
axles together provided the vehicle meets the stability performance 
criteria of S5.2.1 and S5.2.2.
* * * * *
    S5.5.1 Except as provided in S5.5.10, the vehicle manufacturer must 
provide a telltale indicating that the vehicle has been put into a mode 
that renders it unable to satisfy the requirements of S5.2.1, S5.2.2 
and S5.2.3, if such a mode is provided.
* * * * *
    S5.5.4 Except as provided in paragraph S5.4.4, the ``ESC Off'' 
telltale must remain continuously illuminated for as long as the ESC is 
in a mode that renders it unable to satisfy the requirements of S5.2.1, 
S5.2.2, and S5.2.3, and
* * * * *
    S5.5.10 The ``ESC Off'' telltale need not illuminate when the 
vehicle is in a 4-wheel drive high gear locked differential 
configuration that has the effect of locking the drive gears at the 
front and rear axles together provided the vehicle meets the stability 
performance requirements of S5.2.1 and S5.2.2.
* * * * *
    S6.3.1 The ESC system is enabled for all testing, except when it is 
turned off directly or by simulating a malfunction in accordance with 
S7.3 and S7.10, respectively. The ESC system shall be initialized as 
follows: Place the vehicle in a forward gear and obtain a vehicle speed 
of 48  8 km/h (30  5 mph). Drive the vehicle 
for at least two minutes including at least one left and one right 
turning maneuver and at least one application of the service brake.
* * * * *
    S7.10.2 With the vehicle initially stationary and the ignition 
locking system in the ``Lock'' or ``Off'' position, activate the 
ignition locking system to the ``Start'' position and start the engine. 
Place the vehicle in a forward gear and obtain a vehicle speed of 48 
 8 km/h (30  5 mph). Drive the vehicle for at 
least two minutes including at least one left and one right turning 
maneuver and at least one application of the service brake. Verify that 
within two minutes after obtaining this vehicle speed the ESC 
malfunction indicator illuminates in accordance with S5.3.
    S7.10.3 As of September 1, 2011, stop the vehicle, deactivate the 
ignition locking system to the ``Off'' or ``Lock'' position. After a 
five-minute period, activate the vehicle's ignition locking system to 
the ``Start'' position and start the engine. Verify that the ESC 
malfunction indicator again illuminates to signal a malfunction and 
remains illuminated as long as the engine is running or until the fault 
is corrected.
    S7.10.4 Deactivate the ignition locking system to the ``Off'' or 
``Lock'' position. Restore the ESC system to normal operation, activate 
the ignition system to the ``Start'' position and start the engine. 
Place the vehicle in a forward gear and obtain a vehicle speed of 48 
 8 km/h (30  5 mph). Drive the vehicle for at 
least two minutes including at least one left and one right turning 
maneuver and at least one application of the service brake. Verify that 
within two minutes after obtaining this vehicle speed that the ESC 
malfunction indicator has extinguished.
* * * * *

    Issued: September 16, 2008.
David Kelly,
Acting Administrator.
[FR Doc. E8-22067 Filed 9-19-08; 8:45 am]

BILLING CODE 4910-59-P