OBD System Check During State Emission Test
STATE I/M PROGRAM ADVISORY BULLETINNUMBER: 11-55-99
DATE: 03-17-99
APPLICABILITY:
All 1996-2000 Model Subaru Vehicles
SUBJECT:
On-Board Diagnostic System Check During State Emission Test
The U.S. Environmental Protection Agency has issued regulations for inspecting the On-Board Diagnostic (OBD) system as part of the state emission inspections in basic and enhanced I/M programs on 1996 model and newer passenger cars and light duty trucks. The agency has delayed the requirement for OBD system checks in state I/M program from January 1, 1998 to January 1, 2001. However, some states have started their OBD system check inspections earlier than the January 1, 2001 regulatory deadline.
Subaru (and the auto industry) believe it is extremely important that OBD systems are promoted in a good light with the motoring public and those states choosing early system check implementation. In accordance, this bulletin is provided for the proper OBD system inspection of 1996 through 2000 model Subaru vehicles.
A Malfunction Indicator Light (MIL) is to be illuminated whenever an emission-related component has a fault, which could cause the vehicle's emissions to exceed applicable standards. The purpose of this requirement is to alert the vehicle operator of the fault and cause them to seek repair.
Federal regulations require that MIL command status is checked during the test on all affected vehicles with the engine running. The vehicle will fail the OBD check, if the MIL is commanded to be illuminated, and (1) it is not or (2) the MIL light is illuminated and diagnostic trouble codes (DTCs) are present.
In order to meet the regulatory requirements of the MIL bulb check, the MIL for all 1996 through 2000 model Sahara vehicles equipped with an OBD II system is illuminated and commanded "ON" in the key on-engine off(KOEO) position. (If the MIL is checked in the key on-engine running (KOER) position, the MIL will indicate "OFF" assuming no DTCs are present.)
It has been brought to our attention that some decentralized inspection stations or shops may attempt to perform the OBD system check inspection with the vehicle's ignition in the KOEO position in order to preclude running the vehicle's engine inside of the shop. Under this condition, the inspecting shop may incorrectly fail the vehicle for OBD system check.
Both the California Air Resources Board and the U.S. EPA have approved the MIL illumination strategy described above in paragraph 5. However, Subaru plans to revise the current MIL illumination strategy for most 2001 and newer models such that the MIL status is "OFF" in both the KOEO and KOER positions.