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

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Activate the door lock switches to the lock and unlock positions.

Do both rear passenger doors lock and unlock?

Go to Step 3

Go to Power Door Locks Inoperative

3

Did the liftgate lock actuator lock and unlock?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4

  1. Disconnect liftgate door lock actuator.
  2. With a test lamp connected to a good ground, probe the door lock actuator lock circuit at the door lock actuator harness connector.
  3. Activate a door lock switch to lock position.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5

  1. With a test lamp connected to a good ground, probe the door lock actuator unlock circuit at the door lock actuator harness connector.
  2. Activate a door lock switch to unlock position.

Does the test lamp illuminate?

Go to Step 6

Go to Step 8

6

Inspect for poor connections at the harness connector of the door lock actuator. 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 10

Go to Step 9

7

Repair the open the door lock actuator lock circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

--

8

Repair the open in the door lock actuator unlock circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

--

9

Replace the liftgate door lock actuator. Refer to Door Lock Actuator Replacement in Body Rear End.

Did you complete the repair?

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2