GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The body control module (BCM), upon receipt of a door lock switch unlock signal or a keyless unlock command, will supply battery voltage to the passenger door lock actuator unlock control circuits to unlock the passenger doors.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3132 All Door Unlock Circuit Low

Conditions for Running the DTC

    • Battery voltage is between 9-16 volts.
    • The BCM supplies battery voltage to the passenger door lock actuator unlock control circuits.

Conditions for Setting the DTC

    • The BCM does not detect a passenger door unlock relay feedback on the passenger door lock actuator unlock control circuits.
    • The conditions above must be present for more than 0.3 seconds.

Action Taken When the DTC Sets

    • The BCM sets DTC B3132 as current.
    • The passenger door lock actuators will not lock or unlock.

Conditions for Clearing the DTC

    • When the passenger door unlock relay feedback is detected by the BCM during a door unlock operation
    • A current DTC will go to history DTC status after the ignition has been cycled.
    • A history DTC will clear after 100 consecutive fault-free ignition cycles.
    • A scan tool may be used to clear the DTC.

Diagnostic Aids

If the DTC B3132 is accompanied by DTC B3127 and B3137, the fault may be any of the following:

    • An open BCM PWR 15-amp fuse, which could be caused by any of the following:
       - The BCM is shorted to ground internally.
       - Any of the door lock actuator lock or unlock control circuits are shorted to ground.
    • The BCM has an internal open.

If DTC B3132 is set as current and DTCs B3127 and B3137 will not set with multiple lock and unlock switch activations, the BCM is internally open.

Step

Action

Yes

No

Connector End View Reference: Power Door Systems Connector End Views or Computer/Integrating Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Is DTC B3132 set as a current DTC?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Operate a door lock switch to the lock and unlock position multiple times.

Did DTCs B3127 and B3137 also set as current?

Go to Step 4

Go to Step 6

4

Is the body control module (BCM) PWR 15-amp fuse open?

Go to Step 5

Go to Step 6

5

Test for a short to ground in the driver door lock actuator unlock control, the passenger door lock actuator unlock control, and the door lock actuator lock control circuits. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 8

Go to Step 6

6

Inspect for poor connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

7

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 8

--

8

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK