GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

Connector End View Reference: Power Door Systems Connector End Views , Computer/Integrating Systems Connector End Views in Computer/Integrating Systems, or Electrical Center Identification Views in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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 in Wiring System

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. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

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). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

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 supply voltage
    • Passenger door lock switch unlock supply voltage

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

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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

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

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10

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming

Did you complete the replacement?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2