GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Important:

    • Inspect the condition of body control module (BCM), Ign 1 and the cruise fuse (located in the left bussed electrical center LBEC and the mid bussed electrical center MBEC). If any fuse is open, replace the fuse and retest system for intermittent fuse failure. If the fuse continues to fail locate and repair the source of overload. Refer to Power Distribution Schematics.
    • CHECK that Ground G203 and G304 are clean and tight.

1

  1. Turn the ignition switch to run.
  2. Using a scan tool, monitor current DTCs in the body control module (BCM).

Does the scan tool display and current BCM DTCs?

--

Go to appropriate DTC

Go to Step 2

2

Monitor the BCM chime output data display.

Does the scan tool display any chime input data?

--

Go to Step 4

Go to Step 3

3

Replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Is the repair complete?

--

System OK

--

4

Monitor the BCM chime output data display.

Does the scan tool display head lamp data?

--

Go to Step 9

Go to Step 5

5

Monitor the BCM chime output data display.

Does the scan tool display key in data?

--

Go to Step 17

Go to Step 6

6

Monitor the BCM chime output data display.

Does the scan tool display seat belt data?

--

Go to Step 14

Go to Step 7

7

  1. Verify the turn signal switch if off.
  2. Disconnect the BCM connector C1.
  3. Connect a test lamp between CKT 14 (LT BLU) cavity B6 or between CKT 15 (DK BLU) cavity B7 and ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 3

8

Locate and repair short to battery voltage on the circuit 14 or 15 between the BCM and the turn/hazard switch.

Is the repair complete?

--

System OK

--

9

  1. Turn the ignition off.
  2. Verify the headlamp and panel dimmer switch is off.
  3. Disconnect the headlamp relay (located in the underhood bussed electrical center UBEC).

Does the chime stop sounding?

--

Go to Step 10

Go to Step 11

10

Replace the headlamp relay.

Is the repair complete?

--

System OK

--

11

  1. Disconnect the headlamp and the panel dimmer switch connector.
  2. Connect a test lamp between CKT 352 (WHT) cavity C and ground.

Does the test lamp light?

--

Go to Step 12

Go to Step 13

12

Replace the headlamp and the panel dimmer switch. Refer to Headlamp Switch Replacement in Lighting Systems.

Is the repair complete?

--

System OK

--

13

Locate and repair the short to battery voltage on CKT 352 (WHT) between the headlamp and the panel dimmer switch and the BCM.

Is the repair complete?

--

System OK

--

14

Disconnect the seat belt switch connector.

Does the chime stop sounding?

--

Go to Step 15

Go to Step 16

15

Replace the seat belt switch. Refer to Seat Belt Buckle Replacement - Left Front in Seat Belts.

Is the repair complete?

--

System OK

--

16

Locate and repair the short to ground on CKT 238 (BLK/WHT) between seat belt switch and the BCM, or the inflatable restraint sensing and the diagnostic module and the BCM.

Is the repair complete?

--

System OK

--

17

  1. Turn the ignition off.
  2. Remove the key from the ignition switch.
  3. Disconnect the in-line connector C 201B at base of the steering column.

Does the chime stop sounding?

--

Go to Step 18

Go to Step 19

18

Replace the key-in ignition switch on the steering column.

Is the repair complete?

--

System OK

--

19

Locate and repair the short to ground in CKT 80 (LT GRN) between in-line connector C201B and BCM.

Is the repair complete?

--

System OK

--