GM Service Manual Online
For 1990-2009 cars

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

1

Did you review the Power Door Lock Description and Operation?

Go to Step 2

Go to Symptoms - Doors

2

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

Did both doors lock and unlock from both switches?

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

Go to Step 3

3

Did both door lock switches operate 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 control circuit at the door lock actuator connector and a good ground.
  3. Press the door lock switch to the lock position.

Did the test lamp illuminate?

Go to Step 5

Go to Step 12

5

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

Did the test lamp illuminate?

Go to Step 11

Go to Step 13

6

  1. Disconnect the inoperative door lock switch.
  2. Connect a test lamp between the battery positive voltage circuit at the switch connector and a good ground.

Did the test lamp illuminate?

Go to Step 7

Go to Step 14

7

Is the inoperative switch the driver door lock switch?

Go to Step 8

Go to Step 10

8

Connect a test lamp between the door lock control circuit at the driver door lock switch harness connector and B+.

Did the test lamp illuminate?

Go to Step 15

Go to Step 9

9

Connect a test lamp between the door unlock control circuit at the driver door lock switch harness connector and B+.

Did the test lamp illuminate?

Go to Step 16

Go to Step 10

10

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 19

Go to Step 17

11

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 19

Go to Step 18

12

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

Did you complete the repair?

Go to Step 19

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13

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

Did you complete the repair?

Go to Step 19

--

14

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 19

--

15

Repair the short to ground in the door lock control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 19

--

16

Repair the short to ground in the door unlock control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 19

--

17

Replace the door lock switch.

Did you complete the repair?

Go to Step 19

--

18

Replace the door lock actuator. Refer to Power Door Lock Actuator Replacement .

Did you complete the repair?

Go to Step 19

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19

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2