GM Service Manual Online
For 1990-2009 cars only

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 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.

  2. The symptoms list in Symptoms will designate the appropriate diagnostic table to use.

  3. 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.

Step

Action

Yes

No

Schematic Reference: Audible Warnings Schematics

1

Install a scan tool.

Does the scan tool power up?

Go to Step 2

Go to Scan Tool Does Not Power Up in Data Link Communications

2

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with each of the following control modules:
  3. • The dash integration module (DIM)
    • The drivers door module (DDM)
    • The heater and A/C control (w/C67)
    • The inflatable restraint and sensing diagnostic module (SDM)
    • The instrument panel cluster (IPC)
    • The instrument panel module (IPM) (w/CJ2)
    • The radio

Does the scan tool communicate with the all of the indicated control modules?

Go to Step 3

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

3

Select the display DTCs function on the scan tool for each of the following modules:

    • The dash integration module (DIM)
    • The drivers door module (DDM)
    • The heater and A/C control (w/C67)
    • The inflatable restraint and sensing diagnostic module (SDM)
    • The instrument panel cluster (IPC)
    • The instrument panel module (IPM) (w/CJ2)
    • The radio

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms - Instrument Panel, Gages and Console

4

Does the scan tool display DTC U1161, U1162, or U1163?

Go to Diagnostic Trouble Code (DTC) List in Doors

Go to Step 5

5

Does the scan tool display any other DTCs which begin with a "U"?

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

Go to Step 6

6

Does the scan tool display DTC B1000,B1001, B1004, B1007, B1009, B1010, B1390, or B1422?

Go to Diagnostic Trouble Code (DTC) List in Body Control System

Go to Step 7

7

Does the scan tool display DTC B1327, B1513, or B1514?

Go to Diagnostic Trouble Code (DTC) List in Engine Electrical

Go to Diagnostic Trouble Code (DTC) List