GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Verify that all door locks and switches are inoperative.

Do the power door locks operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the doors to lock and unlock.

Do the door lock actuators lock and unlock with each command?

Go to Step 4

Go to Step 5

4

Is the LOCK/MIRROR fuse open?

Go to Step 8

Go to Step 5

5

Is the DR LCK fuse open?

Go to Step 9

Go to Step 6

6

Test the battery positive voltage circuit of the lock switches for an open or high resistance.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

7

Inspect for poor connections at the body control module (BCM).

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

Repair the short to ground in one of the following driver or passenger door lock switch circuits:

    • Battery positive voltage
    • Passenger door lock switch lock control
    • Passenger door lock switch unlock control

Did you complete the repair?

Go to Step 11

--

9

Repair the short to ground in one of the following circuits:

    • Driver door lock actuator unlock control
    • Door lock actuator lock control
    • Door lock actuator unlock control

Did you complete the repair?

Go to Step 11

--

10

Replace the BCM.

Did you complete the replacement?

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2