GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

  1. Close all of the doors.
  2. Turn the ignition switch to the OFF position.
  3. Remove the MALL PGM fuse located in the fuse block.
  4. Turn the ignition switch to the ACC position.

When the BCM enters the feature customization mode, the BCM identifies the type by flashing the fasten belts indicator lamp, and sounding the chime, a number of times equal to the BCM type number.

Does the BCM identify its type number?

Go to Step 2

Go to Cannot Enter BCM Diagnostics

2

Refer to On-Board Diagnostic Features for details on BCM types.

Does the BCM type match vehicle equipment/option content?

Go to Step 3

Go to Step 6

3

Within one second, turn the ignition switch from the ACC position to the OFF position, then back to the ACC position.

Upon cycling the ignition switch as described above, the BCM enters the diagnostic mode. Refer to On-Board Diagnostic Features . At this point, the BCM will flash and chime any diagnostic trouble codes (DTCs) stored in memory, if any.

Is the BCM displaying any DTCs?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 4

4

Enter input testing. Refer to On-Board Diagnostic Features .

Does the BCM respond to the appropriate inputs for the BCM type and RPOs for the vehicle?

Go to Step 5

Go to the appropriate system Diagnostic System Check to diagnose the incorrect inputs

5

Enter output testing. Refer to On-Board Diagnostic Features .

Does the BCM respond with the appropriate outputs for the BCM type and RPOs for the vehicle?

Go to the appropriate Diagnostic System Check for the symptoms reported

Go to the appropriate system Diagnostic System Check to diagnose the incorrect outputs

6

Replace the BCM with the correct BCM type, according to the vehicle equipment content/options. Refer to Body Control Module Replacement .

Is the repair complete?

Go to Step 1

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