GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

1

Did you perform the Power Door System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Door Systems

2

Actuate all the door lock switches to both the lock and unlock positions.

Did all the doors lock and unlock from all of the switches?

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

Go to Step 3

3

Did all of the door lock switches lock and unlock at least one door lock actuator?

Go to Step 4

Go to Step 6

4

  1. Disconnect the inoperative door lock actuator.
  2. Connect a test lamp between the door lock actuator lock circuit at the door lock actuator harness connector and a good ground.
  3. Actuate a door lock switch to the lock position.

Did the test lamp illuminate?

Go to Step 5

Go to Step 9

5

  1. Connect a test lamp between the door lock actuator unlock circuit at the door lock actuator harness connector and a good ground.
  2. Actuate a door lock switch to the unlock position.

Did the test lamp illuminate?

Go to Step 15

Go to Step 10

6

  1. Gain access to the inoperative door lock switch.
  2. Backprobe the door lock switch harness connector with a test lamp, between the battery positive voltage circuit and a good ground.

Did the test lamp illuminate?

Go to Step 7

Go to Step 11

7

  1. Backprobe the door lock switch harness connector with a test lamp, between the door lock control circuit and a good ground.
  2. Actuate the door lock switch to the lock position.

Did the test lamp illuminate?

Go to Step 8

Go to Step 12

8

  1. Backprobe the door lock switch harness connector with a test lamp, between the door unlock control circuit and a good ground.
  2. Actuate the door lock switch to the unlock position.

Did the test lamp illuminate?

Go to Step 14

Go to Step 12

9

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

Did you complete the repair?

Go to Step 17

--

10

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

Did you complete the repair?

Go to Step 17

--

11

Repair the open in the battery positive voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

12

Inspect for poor connections at the door lock switch. 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 17

Go to Step 13

13

Replace the door lock switch.

Did you complete the repair?

Go to Step 17

--

14

Repair the open in the door lock motor lock and/or unlock circuit(s). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

15

Inspect for poor connections at 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 17

Go to Step 16

16

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

Did you complete the repair?

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