From: Robert Jorgensen

Sent: Friday, February 07, 2014 4:31 PM

To: Moulis, Charles

Cc: Jed R. Mandel; Timothy A. Blubaugh; Roger T. Gault

Subject: EMA Suggested Edits to Draft HDOH and Nonroad Maintenance Language

Attachments: Review Draft SCR Regs 012314 - EMA Proposed Edits.docx

Chuck,

Thanks for the opportunity to review the draft changes to the HDOH, LDOH and NR Maintenance 

sections. As we just discussed over the phone, EMA has some suggested edits which we believe provide

additional clarity to the term worst case used in the HDOH and NR draft language. Our suggested edits 

are shown in yellow highlighting on the attached document. In making these edits we took some 

guidance from EPA’s HD OBD provisions for threshold monitors (included below), where the ‘most 

effective’ of the transient test and the SET are to be used.

86.010-18(f)(1). In determining the malfunction criteria for the diesel engine monitors required under 

paragraphs (g) and (i) of this section that are required to indicate a malfunction before emissions exceed 

an emission threshold based on any applicable standard, the manufacturer must:

(i) Use the emission test cycle and standard (i.e., the transient FTP or the supplemental 

emissions test (SET)) determined by the manufacturers to provide the most effective monitoring 

conditions and robust monitor provided all other applicable requirements of this section are 

met....

In addition, as we discussed in an earlier phone call, we would like to have language in the preamble 

that explains that chassis-dyno certified vehicles with gross vehicle weight ratings between 8500 and 

14,000 lbs are subject to the LDOH maintenance provisions.

Don’t hesitate to contact me with any questions or comments you may have. That being said, I am on 

vacation next week. In my absence, please contact Jed, Tim or Roger.

Have a great weekend,

Bob

Robert A. Jorgensen

Truck & Engine Manufacturers Association 

333 West Wacker Drive ▪ Suite 810

Chicago, Illinois ▪ 60606

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Review Draft SCR Regs 012314 - EMA Proposed Edits.docx

HEAVY-DUTY

§ 86.004-25 Maintenance.

* * * * *

(b) * * *

(4) For diesel-cycle heavy-duty engines, emission-related maintenance in addition to or at 

shorter intervals than the following specified values will not be accepted as technologically 

necessary, except as provided in paragraph (b)(7) of this section:

* * * * *

(v) For engines that use selective catalytic reduction, the diesel exhaust fluid (DEF) tank must be 

sized so that the replenishment of diesel exhaust fluid can occur at an interval, in miles or hours 

of vehicle operation, that is no less than the miles or hours of vehicle operation corresponding to 

the vehicle’s fuel capacity. Use good engineering judgment to ensure that you meet this 

requirement for worst case operation. For example, if your highest rate of DEF consumption 

(relative to fuel consumption) will occur under highway driving conditions (characterized by the 

SET or RMCSET), the DEF tank should be large enough that a single tank of DEF would be 

enough to continue proper operation of the SCR system for whatever number of highway miles 

is possible with a single tank of fuel. Analogously, if the highest rate of DEF consumption 

(relative to fuel consumption) will occur under city or urban driving conditions (characterized by 

the transient test), the DEF tank should be large enough that a single tank of DEF would be 

enough to continue proper operation of the SCR system for whatever number of city or urban 

miles is possible with a single tank of fuel. For laboratory engine testing, any size DEF tank 

and/or fuel tank may be used. For our testing of engines, we may require you to provide us with 

a production type DEF tank, including any associated sensors.

* * * * *

(6)(i) The following components are defined as critical emission-related components:

* * * * *

(H) Components comprising the selective catalytic reduction system (including diesel exhaust 

fluid tank).

(I) Any other component whose primary purpose is to reduce emissions or whose failure would 

commonly increase emissions of any regulated pollutant without significantly degrading engine 

performance. 

* * * * *

(ii) All critical emission-related scheduled maintenance must have a reasonable likelihood of 

being performed in-use. The manufacturer shall be required to show the reasonable likelihood of 

such maintenance being performed in-use, and such showing shall be made prior to the 

performance of the maintenance on the durability data vehicle. Critical emission-related 

scheduled maintenance items which satisfy one of the conditions defined in paragraphs (b)(6)(ii) 

(A)-(F) of this section will be accepted as having a reasonable likelihood of the maintenance 

item being performed in-use, except that for DEF replenishment, the manufacturer must satisfy 

paragraph (b)(6)(ii)(A) or (F) for us to accept that there is a reasonable likelihood of the 

maintenance item being performed in-use.

* * * * *
Review Draft SCR Regs 012314 - EMA Proposed Edits.docx

LIGHT-DUTY 

§ 86.1834-01 Allowable maintenance.

* * * * *

(b) * * *

(4) For diesel-cycle vehicles, emission-related maintenance in addition to, or at shorter intervals 

than the following will not be accepted as technologically necessary, except as provided in 

paragraph (b)(7) of this section:

* * * * *

(iii) For vehicles that use selective catalytic reduction, the replenishment of diesel exhaust fluid 

shall occur at an interval that is no less than 4,000 miles for typical operation. 

* * * * *

(6) * * *

(i) * * *

(H) Components comprising the selective catalytic reduction system (including diesel exhaust 

fluid tank).

(I) Any other component whose primary purpose is to reduce emissions or whose failure would 

commonly increase emissions of any regulated pollutant without significantly degrading engine 

performance.

* * * * *

(ii) All critical emission-related scheduled maintenance must have a reasonable likelihood of 

being performed in use. The manufacturer shall be required to show the reasonable likelihood of 

such maintenance being performed in use, and such showing shall be made prior to the 

performance of the maintenance on the durability data vehicle. Critical emission-related 

scheduled maintenance items which satisfy one of the conditions defined in paragraphs (b)(6)(ii) 

(A)-(F) of this section will be accepted as having a reasonable likelihood of the maintenance 

item being performed in-use, except that for DEF replenishment, the manufacturer must satisfy 

paragraph (b)(6)(ii)(A) or (F) of this section for us to accept that there is a reasonable likelihood 

of the maintenance item being performed in-use.
Review Draft SCR Regs 012314 - EMA Proposed Edits.docx

NONROAD

§ 1039.125 What maintenance instructions must I give to buyers?

* * * * *

(a) * * *

(1) You demonstrate that the maintenance is reasonably likely to be done at the recommended 

intervals on in-use engines. We will accept scheduled maintenance as reasonably likely to occur 

if you satisfy any of the following conditions, with the exception that paragraphs (a)(1)(ii) and 

(iii) of this section do not apply for DEF replenishment:

* * * * *

(2) * * *

(iii) For SCR systems, the minimum interval for replenishing the diesel exhaust fluid is the 

number of engine operating hours necessary to consume a full tank of fuel starting from full fuel 

capacity for the equipment. Use good engineering judgment to ensure that you meet this 

requirement for worst case operation. For example, if your highest rate of DEF consumption 

(relative to fuel consumption) will occur under steady state operating conditions (characterized 

by the applicable steady-state certification test), the DEF tank should be large enough that a 

single tank of DEF would be enough to continue proper operation of the SCR system for 

whatever number of steady state hours is possible with a single tank of fuel. Analogously, if the 

highest rate of DEF consumption (relative to fuel consumption) will occur under transient 

operating conditions (characterized by the nonroad transient test), the DEF tank should be large 

enough that a single tank of DEF would be enough to continue proper operation of the SCR 

system for whatever number of transient operating hours is possible with a single tank of fuel.

For laboratory engine testing, any size DEF tank and/or fuel tank may be used. For our testing of 

engines, we may require you to provide us with a production type DEF tank, including any 

associated sensors.

(3) * * *

(iii) For SCR systems, the minimum interval for replenishing the diesel exhaust fluid is the 

number of engine operating hours necessary to consume a full tank of fuel starting from full fuel 

capacity for the equipment. Use good engineering judgment to ensure that you meet this 

requirement for worst case operation. For laboratory engine testing, any size DEF tank and/or 

fuel tank may be used. For our testing of engines, we may require you to provide us with a 

production type DEF tank, including any associated sensors.

* * * * *