GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Rendezvous - AWD 🢒 Accessories 🢒 Navigation Systems 🢒 DTC B3272

Circuit Description

The door lock switch provides a direct ground input to the body control module (BCM) when the door lock switch is activated to the unlock position. This input is used by the BCM to control the door locks.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3272 Door Unlock Switch Circuit

Conditions for Setting the DTC

The BCM detects a short to ground in the driver door lock switch signal circuit for greater than 60 seconds.

Action Taken When the DTC Sets
    • The BCM stores DTC B3272 in memory.
    • The BCM will disable the input and all operations of the input until the fault no longer exists.

Conditions for Clearing the DTC
    • The BCM no longer detects the short to ground in the driver door lock switch signal circuit for greater than 60 seconds.
    • 100 consecutive ignition cycles have been recorded without the DTC being detected.

Diagnostic Aids
    • If the DTC B3272 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • The following conditions may cause an intermittent malfunction to occur:
       - An intermittent short to ground in the driver door lock switch lock signal circuit
       - The door lock switch is intermittently shorted to ground internally
       - The BCM is intermittently shorted to ground internally

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Determines whether the DTC is current or intermittent.

    2.

  2. Determines whether the driver door lock switch lock signal circuit or a door lock switch is shorted to ground.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

Connector End View Reference: Power Door Systems Connector End Views , Computer/Integrating Systems Connector End Views in Computer/Integrating Systems, or Electrical Center Identification Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Door Unlock Switch parameter in the body control module (BCM) data list.

Does the scan tool display Inactive?

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the driver and front passenger door lock switches.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Door Unlock Switch parameter in the BCM data list.

Does the scan tool display Inactive?

Go to Step 4

Go to Step 5

4
  1. Turn OFF the ignition.
  2. Connect the driver door lock switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Door Unlock Switch parameter in the BCM data list.

Does the scan tool display Inactive?

Go to Step 7

Go to Step 8

5

Test the driver door lock switch lock signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

7

Replace the driver door lock switch. Refer to Door Lock Switch Replacement .

Did you complete the replacement?

Go to Step 10

--

8

Replace the front passenger door lock switch. Refer to Door Lock Switch Replacement .

Did you complete the replacement?

Go to Step 10

--

9

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

10
  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