GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the Automatic Door Locks System Check performed?

--

Go to Step 2

Go to Power Door Locks System Check

2

Was the Body Control Module (BCM) Diagnostic System Check performed?

--

Go to Step 3

Go to Diagnostic System Check - Body Control System

3

  1. Turn the ignition switch to the LOCK position.
  2. Connect a digital multimeter (DMM) to the data link connector (DLC).
  3. Turn the ignition switch to the RUN position.
  4. Monitor the unlock and lock switch input on the DMM.
  5. While observing the DMM press unlock and lock on the drivers side door lock switch.

Upon pressing unlock and lock, does the DMM indicate unlock and lock switch status as active?

--

Go to Step 5

Go to Step 4

4

  1. Turn the ignition switch to the lock position.
  2. Disconnect the drivers side door lock switch.
  3. Connect a test light between B+ and the drivers side door lock switch harness connector terminal F.

Does the test light illuminate?

--

Go to Step 10

Go to Step 8

5

  1. Using the Tech 2, select the output status.
  2. While observing Tech 2, press lock on driver door switch.

Did Tech 2 indicate output status change?

--

Go to Step 6

Go to Step 7

6

Repair a poor connection or open in CKT 295.

Has the repair been made?

--

Go to Step 9

--

7

  1. Inspect for a poor connection at the BCM.
  2. If the connection is OK, replace the BCM. Refer to Body Control Module Replacement in Body Control System.
  3. After BCM replacement, perform the Setup New BCM Procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Has the repair been made?

--

Go to Step 9

--

8

Repair a poor connection or open in CKT 750.

Has the repair been made?

--

Go to Step 9

--

9

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect the connectors.
  3. Reinstall the components.

Have all the repairs been made?

--

Go to Power Door Locks System Check

--

10

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect the door lock switch.
  3. Disconnect the body control module (BCM) connector C1.
  4. Connect a digital multimeter (DMM).
  5. Measure the voltage between the BCM harness connector C1 terminal D12 and B+.

Is the voltage within the specified range?

9-14 V

Go to Step 11

Go to Step 12

11

Repair a short to ground in CKT 780.

Has the repair been made?

--

Go to Step 9

--

12

  1. Disconnect the drivers side door lock switch.
  2. Connect a DMM.
  3. Check continuity between the BCM harness connector C1 terminal D12 and the door lock switch harness connector terminal C.

Is there continuity?

--

Go to Step 14

Go to Step 13

13

Repair a poor connection or open in CKT 780.

Has the repair been made?

--

Go to Step 9

--

14

  1. Connect a digital multimeter (DMM).
  2. Measure the voltage between the BCM harness connector C1 terminal D13 and B+.

Is the voltage within the specified range?

9-14 V

Go to Step 15

Go to Step 16

15

Repair a short to ground in CKT 781.

Has the repair been made?

--

Go to Step 9

--

16

  1. Connect a DMM.
  2. Check the continuity between the BCM harness connector C1 terminal D13 and the door lock switch harness connector terminal B.

Is there continuity?

--

Go to Step 7

Go to Step 17

17

Repair a poor connection or open in CKT 781.

Has the repair been made?

--

Go to Step 9

--