GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: The door lock switches are not able to unlock the doors. However, the switches can lock the doors.

1

Was the BCM diagnostic system check performed?

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Go to Step 2

Go to Diagnostic System Check - Body Control System

2

  1. Press UNLOCK on the keyless entry transmitter. The theft deterrent indicator LED is flashing.
  2. Press UNLOCK on either door lock switch if the vehicle is not equipped with the content theft deterrent (RPO UA6).

Door the door locks unlock?

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Go to Step 6

Go to Step 3

3

Use a test lamp in order to backprobe between B+ and the BCM connector C2 terminal C6.

Does the test lamp remain off?

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Go to Step 4

Go to Step 5

4

  1. Ensure that the test lamp is connected.
  2. Press UNLOCK on either door lock switch.

Does the test lamp light?

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Go to Step 8

Go to Step 7

5

  1. Ensure that the test light is connected.
  2. Disconnect both door lock switches, one switch at a time.

Is the test light on?

--

Go to Step 9

Go to Step 10

6

Ensure that the content theft deterrent was not armed while trying to unlock the doors. Refer to Automatic Door Lock Circuit Description.

Is the repair complete?

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Go to Automatic Door Locks System Check

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7

Repair the poor connection or an open in circuit 194.

Is the repair complete?

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Go to Step 11

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8

  1. Inspect the BCM connector C2 terminal C6 for a poor terminal contact. Repair the terminal as needed.
  2. If the BCM connector C2 terminal C6 is OK, replace the BCM Refer to Body Control Module Replacement in Body Control Systems.

Is the repair complete?

--

Go to Step 11

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9

Repair the short to ground in circuit 194.

Is the repair complete?

--

Go to Step 11

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10

This causes a ground signal in circuit 194 at all times (switch terminal D). Replace the door lock switch with the internal contact closed. Refer to Front Side Door Lock Replacement or Lock Replacement - Sliding Door Front in Doors.

Is the repair complete?

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Go to Step 11

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11

  1. Turn the ignition switch to the LOCK position.
  2. Re-install any connectors/components that were removed.
  3. Turn the ignition switch to the ACC position. (The BCM sounds the chime a number of times equivalent to the BCM type installed on the vehicle).
  4. Turn the ignition switch from the ACC position, to the LOCK position and back to the ACC position within 1 second. (The BCM sounds any DTCs stored).

Are there any BCM DTCs present?

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Go to Diagnostic System Check - Body Control System

Go to Automatic Door Locks System Check