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

DEFINITION: The driver door lock actuator or lock switch does not operate.

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 the Power Door Lock Inoperative - Driver Door fault is present.

Do the door locks operate as described in the Power Door Locks Description and Operation?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Close all of the vehicle doors.
  3. With the scan tool, observe the LF Door Lock Switch parameter in the Data Display, Inputs list of the body control module (BCM).
  4. Operate the driver door lock switch to both the lock and unlock positions.

Did the parameter change to both the Lock and Unlock states?

Go to Step 6

Go to Step 4

4

Important:: If the 3-amp fuse of the jumper wire opens when the jumper wire is connected, test the appropriate signal circuit for a short to voltage.

  1. Disconnect the harness connector of the driver door lock switch.
  2. Connect a 3-amp fused jumper wire between the lock switch lock signal circuit of the harness connector and a good ground.
  3. Observe the LF Door Lock Switch parameter.
  4. Connect the 3-amp fused jumper wire between the lock switch unlock signal circuit of the harness connector and a good ground.
  5. Observe the LF Door Lock Switch parameter.

Did the scan tool parameter change to the both the Lock and Unlock states?

Go to Step 5

Go to Step 7

5

Connect the 3-amp fused jumper wire between the lock switch lock signal circuit and the ground circuit of the harness connector while observing the appropriate scan tool parameter.

Did the scan tool parameter change to the Lock state?

Go to Step 10

Go to Step 13

6

  1. Disconnect the harness connector of the driver door lock actuator.
  2. Connect a test lamp between the door lock actuator lock control circuit and the door lock actuator unlock control circuit of the harness connector.
  3. Operate the driver door lock switch to the LOCK and UNLOCK positions.

Did the test lamp illuminate in both positions?

Go to Step 12

Go to Step 8

7

Test the signal circuits of the driver door lock switch for a short to ground or an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 11

8

Test the lock control circuit of the driver door lock actuator for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 9

9

Test the unlock control circuit of the driver door lock actuator for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 11

10

Inspect for poor connections at the harness connector of the driver door lock switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 14

11

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 15

12

Inspect for poor connections at the harness connector of the driver door lock actuator. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 16

13

Repair the open ground circuit of the driver door lock switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

14

Replace the driver door lock switch. Refer to Door Lock and Side Window and Outside Rearview Mirror Remote Control Switch Replacement .

Did you complete the replacement?

Go to Step 17

--

15

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 17

--

16

Replace the driver door lock actuator. Refer to Front Side Door Lock Actuator Replacement .

Did you complete the replacement?

Go to Step 17

--

17

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2