GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform A Diagnostic System Check - Door Systems?

--

Go to Step 2

Go to Diagnostic System Check - Door Systems

2

Verify that the fault is present.

Does the system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Connect a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Using the scan tool, command the door locks to lock and unlock.

Do all of the door locks lock and unlock when commanded by the scan tool?

--

Go to Step 4

Go to Step 8

4

Test the input circuit of the door lock switch to the BCM for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 5

5

Test the ground circuit to the door lock switches for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 6

6

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 15

Go to Step 7

7

Replace the defective door lock switch. Refer to Door Lock Switch Replacement .

Is the repair complete?

--

Go to Step 15

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8

  1. Disconnect the inoperative door lock actuator wiring at the door inline connector.
  2. Using a test lamp on the body side of the vehicle, probe between the feed circuits of the inline connector to the door lock actuator and ground.
  3. Using the scan tool, command the door locks to lock and unlock while observing the test lamp.

Did the test lamp flash when the door locks were commanded to lock and unlock?

--

Go to Step 11

Go to Step 9

9

Test the feed circuits to the door lock actuator on the body side of the vehicle for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

Repair a poor connection in the unlock feed circuit or the lock feed circuit on the body side of the vehicle.

Did you complete the repair?

--

Go to Step 15

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11

  1. Reconnect the door inline connectors to the body.
  2. Disconnect the door lock actuator connector.
  3. Using a test lamp, probe the door lock actuator connector.
  4. Using the scan tool, command the door locks to lock and unlock while observing the test lamp.

Did the test lamp flash when the door locks were commanded to lock and unlock?

--

Go to Step 13

Go to Step 12

12

Test the door lock actuator feed circuits in the door harness wiring for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

13

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 15

Go to Step 14

14

Replace the door lock actuator. Refer to one of the following procedures:

Did you complete the repair?

--

Go to Step 15

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15

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3