GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The SERVICE AWD indicator is located in the instrument panel cluster (IPC). The rear differential clutch control module, controls the SERVICE AWD indicator by sending the IPC a Class 2 message. This indicator may be controlled with the scan tool using the IPC output controls.

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step determines whether the failure is the result of a faulty rear differential clutch control module or the IPC.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn the ignition ON, with the engine OFF.
  2. Install a scan tool.
  3. Using the scan tool go to instrument panel cluster output controls.
  4. Use the scan tool in order to command the SERVICE AWD Message OFF.

Does the SERVICE AWD Message turn OFF?

Go to Step 3

Go to Symptoms - Displays and Gages in Instrument Panel, Gages, and Console

3

Replace the rear differential clutch control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the repair?

Go to Step 4

--

4

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle in order to determine if the symptom has been corrected.

Is the symptom still present?

Go to Step 2

System OK