GM Service Manual Online
For 1990-2009 cars only

Test Description

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

  1. Tests if the BCM can enter the On-Board Diagnostic Mode. Refer to On-Board Diagnostic Features .

  2. Tests the presence of DTCs stored in the BCM. Refer to the Diagnostic Trouble Code (DTC) List for the appropriate procedure.

Step

Action

Yes

No

Schematic Reference: Body Control System Schematics

1

Enter the BCM Diagnostic Mode. Refer to On-Board Diagnostic Features .

Does the BCM enter the Diagnostic Display mode?

Go to Step 2

Go to Cannot Enter BCM Diagnostics

2

Select display BCM DTCs. Refer to On-Board Diagnostic Features .

Does the BCM display any DTCs?

Go to Diagnostic Trouble Code (DTC) List

Go to the Applicable Symptom Table