GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Neither of the door switches can lock the doors. Both of the switches can lock the doors.

1

Was the Automatic Door Locks System Check performed?

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Go to Step 2

Go to Automatic Door Locks System Check

2

Did you perform the BCM diagnostic check?

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Go to Step 3

Go to Diagnostic System Check - Body Control System in Body Control System

3

  1. Verify that the key is removed from the ignition cylinder.
  2. Verify that all of the doors are closed.
  3. Press lock on either of the door lock switches.

Do the doors lock?

--

Go to Step 7

Go to Step 4

4

Use a test light in order to probe between B+ and the BCM connector C2 terminal C7.

Does the test light illuminate?

--

Go to Step 6

Go to Step 5

5

  1. Leave the test light connected.
  2. Press LOCK on either one of the door lock switches and observe the test light.

Does the test light illuminate?

--

Go to Step 9

Go to Step 8

6

  1. Leave the test light connected.
  2. Disconnect both of the door lock switches, one at a time. Observe the test light.

Does the test light illuminate after disconnecting both switches?

--

Go to Step 10

Go to Step 11

7

  1. Activate the lockout feature. Refer to Power Door Locks Circuit Description .
  2. Attempt to lock the doors.

Is the repair complete?

--

Go to Step 12

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8

Repair the poor connection or the open in circuit 195.

Is the repair complete?

--

Go to Step 12

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9

  1. Inspect the BCM connector C2 terminal C7 for a poor terminal contact.
  2. Repair the terminal as needed.
  3. If the terminal does not require repair, replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

--

Go to Step 12

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10

Repair the short to ground in circuit 195.

Is the repair complete?

--

Go to Step 12

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11

Replace the door lock switch with the internal contact closed at all times.

Is the repair complete?

--

Go to Step 12

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12

  1. Turn the ignition switch to the OFF position.
  2. Reconnect all of the connectors.
  3. Reinstall all of the components.
  4. Turn the ignition switch to the RUN position for 6 seconds.
  5. Turn the ignition switch to the OFF position.
  6. Remove the MALL PGM fuse.
  7. Turn the ignition switch to the ACC position.
  8. The BCM sounds the chime a number of times equivalent to the BCM type installed on the vehicle.

  9. Within one second, turn the ignition switch from the ACC position to the OFF position, then back to the ACC position. The BCM sounds any stored DTCs.

Are any BCM DTCs present?

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Go to Diagnostic System Check - Body Control System in Body Control System

Go to Automatic Door Locks System Check