Test Description
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The number(s) below refer to the step number(s) on the diagnostic table.
- 2) - Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
- 3) - The presence of DTCs indicates that the transfer case shift control module has detected a fault. Go to symptoms for other concerns.
- 4) - The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
- 5) - Vehicle speed is provided to the transfer case shift control module via Class 2. Perform the diagnostics for powertrain DTCs P0502 and P0503 first.