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OAR Box 1190 

Prepped by Candice Davis 

Document Number: 

71) II-E-1 

Docket Number: 

A-90-28 

Printed 5/5/2008 9:13:51 AM Sheet 71 of 106 
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J.-K 

MEMORANDUM 

TO: Andy Brooks/OBD II File 

FROM: David Dickinson \\Vs 

DATE: 9/23/91 ^ ^ 

RE: Summary of 9/12/91 CARB public hearing for OBD 

status and proposed revisions 

technical 

The following notations are specific points made during the 

hearing which either were particularly significant in relation to 

the prior proposed OBD II rule or could perhaps affect EPA's waiver 

consideration. 

In general the CARB staff concluded that most manufacturers 

were on schedule to implement OBD II systems (at least a portion of 

their vehicles) by the 1994 model year—the first year of OBD II 

implementation. The Board agreed with the staff conclusion, 

despite manufacturer dispute, and adopted the changes in order to 

open up a further written comment period. The CARB staff stated it 

may consider a scheduled implementation plan (a certain percentage 

of fleet compliance in '94,'95 model years with full compliance in 

'96) in response to manufacturer claims that they are still 

developing technology. 

CARB is keeping their public comment period open through midOctober 1991, and expects to submit a waiver request to EPA 

sometime between March and July 1992, dependent upon the number of 

comments, workshop, etc. CARB announced that in September 1992 it 

will hold another public hearing in Sacramento to monitor 

manufacturer technical status and amend OBD II if necessary. It is 

not clear how such amendments would be treated within the context 

of a waiver request. 

The following are the notations mentioned above, coupled with 

responses made by manufacturers (manufacturers complained that they 

thought present meeting was for sole purpose of checking their 

technical status with the prior OBD II requirements. Manufacturers 

claimed they were only put on notice of CARB's changes to OBD II 

the week prior to the hearing and were thus not prepared to give 

full comment on the proposed changes): 

1. Catalyst Monitoringa. Evaluate efficiency over FTP as opposed to single steady 

speed driving condition. - manufacturers wanted to reserve comment 

on this. 

b. For lead time "steady speed" will be allowed for '94 and 

'95 Mys. 
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/ 

2. Evaporative Monitoringa. New proposal seeks a more effective monitoring system to 

detect a system leak equivalent to a 0.04 inch diameter orifice. 

Manufacturers commented that technology was not currently available 

to do this and they were not sure what size orifice could be 

detected, Board suggested to look at this again in Sept. 1992 when 

new evaporative emission regulations are in place. 

b. This requirement would become effective concurrent with new 

standards/test procedures for evap. emissions, which some thought 

to be after 1994. 

3. Fuel Cap Monitoringa. If manufacturer's system is capable of detecting when fuel 

cap is not fastened, fault code would be erased and MIL 

extinguished (if no other malfunctions) upon fastening. 

Manufacturers thought this feasible. 

4. OBD II vs. Federal OBD 

a. Proposed that non-LEVs (which will be 48% of fleet in 1998, 

23% in 1999, 0% thereafter-according to implementation rates Table 

for fleet average standards for passenger cars) designed to meet 

federal OBD would be accepted in California after 1998 model year, 

in order to employ a single OBD design. Manufacturers stated that 

they thought CARB policy was to allow manufacturers to develop one 

OBD system for both California and EPA requirements. Implementation 

of fed OBD requirements should go into effect in 1994 according to 

NPRM published 9/24/91. Since CARB plans to make MIL illumination 

optional in certain circumstances (see 5f below) it is unclear 

whether CARB will allow cars to meet only EPA requirements or 

whether EPA will allow CARB cars for the '94 and '95 model years. 

5. Other modificationsa. MIL would not blink unless misfire was at level to cause 

actual catalyst damage- in this context ah additional trip would be 

allowed to verify presence of misfire. 

b. A monitoring system would be required on all vehicles using 

CFC refrigerants in order to detect leaking- most manufacturers 

stated that they hoped to avoid this requirement with the use of 

substitutes or that CFCs were to be phased out by law anyway and 

thus they thought research and technology to monitor such leaks was 

not cost effective, CARB staff maintained that this monitoring was 

still necessary until ban on CFCs became law. 

c. Storage of "freeze frame" conditions would be required for 

malfunctions other than misfire/fuel system problems in order to 

determine exact conditions(speed,HP, coolant temperature, etc.) of 

vehicle when malfunction occurred. Manufacturers were in general 

consensus that the technology to record freeze frame conditions 
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does not currently exist and that they were not sure how many 

"sets" of conditions the OBD must record in relation to the number 

of malfunctioning occurrences. In other words MIL illumination is 

not required in some instances until a malfunction occurs several 

times, thus manufacturers were concerned that freeze frame 

recording would be required for each malfunction and were unsure 

how long such information should be stored. In addition, 

manufacturers stated that it would be impossible for mechanics to 

reproduce freeze frame conditions in order to check the validity of 

their repairs. 

d. Proposed that MIL would be illuminated when key is turned 

but extinguished after car has started. Manufacturers thought that 

they could comply with some universal MIL language on the vehicle 

instrument panel. 

e. Starting in 1994 CARB wants to recall the OBDs if they are 

malfunctioning themselves, regardless of whether vehicle is meeting 

emission standards. Several manufacturers worried that this might 

be an incentive to not install OBDs until required to do so, thus 

discouraging manufacturers to "test" or experiment with their OBD 

technology with cars in use. 

f. 1994 and 1995 model years will not require (optional) MIL 

illumination for EVAP, misfire and catalyst malfunctions- theory is 

that manufacturers will be experimenting with technology and do not 

want customer dissatisfaction/distrust of OBD system. (Computer 

will nevertheless record applicable malfunction codes) 

There was very little discussion of actual cost-per-vehicle 

for the OBD system though several members of the CARB board 

expressed concern with the CARB staff's figure of approximately 

$20.00. Manufacturers were also doubtful od this low figure but 

were unable to supply a cost estimate since technology is not 

completely developed. I am currently reviewing EPA's NPRM for OBD 

and comparing it with CARB's proposal to determine consistency and 

whether there are any gaps between when both come into effect or 

allow the other system to meet its own standards. 

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