State I/M Program Advisory Bulletin
NUMBER: 11-50-97DATE: 12/5/97
APPLICABILITY
All Subaru Full-Time AWD Models
SUBJECT
State Emission Testing
This is a reprint of Subani Bulletin 11-45-95 that includes additional information.
!WARNING!
Testing of a Full-Time 4WD or All-Wheel Drive Vehicle must never be performed on a single two-wheel dynamometer, nor should a state I/M program inspector or its contractors install the FWD fuse in the engine compartment. Attempting to do so will result in uncontrolled vehicle movement and may cause an accident or injuries to persons nearby.
!CAUTION!
Resultant vehicle damage due to improper testing is not covered under the SUBARU Limited Warranty and is the responsibility of the STATE I/M Program or its contractors or licensees.
The 1990 Clean Air Act Amendments require the Environmental Protection Agency (EPA) to implement programs to reduce air pollution from motor vehicles. States are required to adopt either a "basic" or "enhanced" vehicle Inspection/Maintenance I/M) Program depending on the severity of their air pollution problem. The "enhanced" I/M test simulates actual driving conditions on a dynamometer and permits more accurate measurement of tailpipe emissions than the "basic" I/M test which measures emissions only during engine operating conditions at idle and 2500 RPM. The "Enhanced" I/M test also includes a pressure check to identify evaporative emissions leaks in the fuel system.
The US EPA has exempted SUBARU Full-Time All-Wheel Drive (AWD) vehicles from the following performance warranty short tests:
^ Loaded Test
^ Idle Test With Loaded Preconditioning
The exemption language is specified on the underhood Vehicle Emission Control Information (VECI) label as shown in Figure 1.
State I/M Programs should test affected SUBARU Full-Time AWD models using any other EPA approved performance warranty short test. SUBARU models equipped with the Full-Time AWD feature should be tested on a four-wheel drive dynamometer (State I/M Program may elect to use a "double two-wheel dynamometer" arrangement). Under NO circumstances should any Subaru Full-Time AWD equipped vehicle be modified for I/M testing. This prohibition includes, but is not limited to: (1) jacking the rear wheels off the ground, (2) driveshaft disconnection, and/or (3) usage of the FWD fuse in the engine compartment. This fuse is for Full-Time 4WD or AWD diagnostic service purposes.
For vehicles with the Traction Control System (TCS), the TCS off switch on the dash must be placed in the "off" position after starting the engine, but prior to any testing on the dynamometer.
Listing of 1987-1998 Model Subaru Full-Time 4WD and AWD Drive Vehicles
Listing of 1987-1998 Model Subaru Full-Time 4WD and AWD Drive Vehicles
Listing of Traction Control System Equipped Models