GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Door Locks System Check?

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Go to Step 2

Go to Power Door Locks System Check

2

  1. Enter the body control module (MALL) diagnostic mode.
  2. Press and hold the power door unlock switch.
  3. Cycle the headlamps ON and OFF 6 times.
  4. Release the power door unlock switch.
  5. The MALL may sound a series of tones (history codes) upon entering the diagnostic mode. Refer to Body Control Module Diagnostic Information in Body Control System.
  6. Press a door lock switch to the UNLOCK position, then to the LOCK position.
  7. Does the MALL sound one tone for each press of the door lock or unlock switch?

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Go to Step 4

Go to Step 3

3

  1. Use a J 39200 digital multimeter (DMM) in order to backprobe the MALL connector C1 between terminal A and terminal C.
  2. Press the door lock switch to the LOCK position.

Is the voltage within the specified range?

10-15 V

Go to Step 8

Go to Step 5

4

  1. Turn OFF the ignition switch.
  2. Disconnect the MALL connector C1.
  3. Disconnect the left front door lock actuator connector C2.
  4. Use the DMM inorder to measure the resistance between connector C1 terminal A and connector C2 terminal A.

Is the resistance zero?

0 ohms

Go to Step 6

Go to Step 8

5

With the DMM still connected, press the door lock switch to the UNLOCK position.

Is the voltage within the specified range?

10-15 V

Go to Power Door Locks System Check

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6

Replace the MALL. Refer to Body Control Module Replacement in Body Control System.

Did you complete the repair?

--

Go to Power Door Locks System Check

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7

  1. Use the DMM in order to backprobe any door lock actuator connector between terminal B and ground.
  2. Press the door lock switch to the LOCK position.

Is the voltage within the specified range?

10-15 V

Go to Step 9

Go to Step 8

8

Repair an open in CKT 295 (GRY). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Power Door Locks System Check

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9

Repair an open in CKT 694 (TAN). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Power Door Locks System Check

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