GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Neither one of the door lock switches can unlock the doors. The door lock switches can lock the doors.

1

Was the Automatic Door Lock System Check performed?

--

Go to Step 2

Go to Automatic Door Locks System Check

2

Did you perform the BCM diagnostic system check?

--

Go to Step 3

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

3

Determine if the vehicle is equipped with the content theft deterrent (RPO UA6).

Is the vehicle equipped with the content theft deterrent?

--

Go to Step 4

Go to Step 5

4

  1. If the theft deterrent indicator LED is flashing, press UNLOCK on the keyless entry transmitter.
  2. Press UNLOCK on either door lock switch.

Do the door locks unlock?

--

Go to Step 8

Go to Step 5

5

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

Does the test light illuminate?

--

Go to Step 7

Go to Step 6

6

  1. Leave the test light connected.
  2. Observe the test light and press UNLOCK on either door lock switch.

Does the test light illuminate?

--

Go to Step 10

Go to Step 9

7

  1. Leave the test light connected.
  2. Observe the test light and disconnect one of the door lock switches.
  3. Observe the test light and disconnect the other door lock switch.

Does the test light still illuminate?

--

Go to Step 11

Go to Step 12

8

Verify that the content theft deterrent was not disarmed when you attempted to unlock the doors. Refer to Content Theft Deterrent (CTD) Operation in Theft Deterrent.

Is the repair complete?

--

Go to Step 13

--

9

Repair the poor connection or the open in circuit 194.

Is the repair complete?

--

Go to Step 13

--

10

  1. Inspect the BCM connector C2 terminal C6 for a poor terminal contact.
  2. Repair the terminal as needed.
  3. If the BCM connector C2 terminal C6 does not require repair, replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

--

Go to Step 13

--

11

Repair the short to ground in circuit 194.

Is the repair complete?

--

Go to Step 13

--

12

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

Is the repair complete?

--

Go to Step 13

--

13

  1. Turn the ignition switch to the OFF position.
  2. Connect the connectors.
  3. Install any components that you removed.
  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. The chime sounds a number of times that is equivalent to the BCM type that is installed on the vehicle.

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

Are any BCM DTCs present?

--

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

Go to Automatic Door Locks System Check