GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Verify that one door lock switch or actuator is inoperative fault is present.

Do the power door locks operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Is the door lock switch the inoperative component?

Go to Step 4

Go to Step 6

4

Are both the LOCK and UNLOCK functions inoperative?

Go to Step 10

Go to Step  5

5

Is the LOCK function the inoperative function?

Go to Step 11

Go to Step 12

6

Is the driver door lock actuator the inoperative component?

Go to Step 7

Go to Step 8

7

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

Does the test lamp illuminate?

Go to Step 16

Go to Step 13

8

  1. Disconnect the appropriate lock actuator.
  2. Connect a test lamp between the lock actuator unlock control circuit and the lock actuator lock control circuit of the appropriate lock actuator electrical connector.
  3. Activate a door lock switch to the LOCK position.

Does the test lamp illuminate?

Go to Step 9

Go to Step 14

9

Activate a door lock switch to the UNLOCK position.

Does the test lamp illuminate?

Go to Step 17

Go to Step 15

10

Test the battery positive voltage circuit from the LOC/MIRROR fuse to the door lock switch for an open.

Did you find and correct the condition?

Go to Step 25

Go to Step 18

11

Test the driver door lock switch lock signal circuit for an open or short to battery.

Did you find and correct the condition?

Go to Step 25

Go to Step 19

12

Test the driver door lock switch unlock signal circuit for an open or short to battery.

Did you find and correct the condition?

Go to Step 25

Go to Step 19

13

Test the driver door lock actuator unlock control circuit for an open or short to battery.

Did you find and correct the condition?

Go to Step 25

Go to Step 15

14

Test the appropriate lock actuator lock control circuit for an open or short to battery.

Did you find and correct the condition?

Go to Step 25

Go to Step 20

15

Test the appropriate lock actuator unlock control circuit for an open or short to battery.

Did you find and correct the condition?

Go to Step 25

Go to Step 20

16

Inspect for poor connections at the driver door lock actuator.

Did you find and correct the condition?

Go to Step 25

Go to Step 21

17

Inspect for poor connections at the appropriate lock actuator.

Did you find and correct the condition?

Go to Step 21

Go to Step 21

18

Inspect for poor connections at the appropriate door lock switch.

Did you find and correct the condition?

Go to Step 25

Go to Step 21

19

Inspect for poor connections at the body control module (BCM).

Did you find and correct the condition?

Go to Step 25

Go to Step 23

20

Inspect for poor connections at the I/P fuse block harness connectors.

Did you find and correct the condition?

Go to Step 25

Go to Step 24

21

Replace the appropriate lock actuator.

Did you complete the repair?

Go to Step 25

--

22

Replace the appropriate door lock switch.

Did you complete the repair?

Go to Step 25

--

23

Replace the BCM.

Did you complete the replacement?

Go to Step 25

--

24

Replace the appropriate door lock relay.

Did you complete the repair?

Go to Step 25

--

25

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2