GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Rendezvous - FWD 🢒 Accessories 🢒 Navigation Systems 🢒 DTC B3270

Circuit Description

The driver and front passenger door lock switches provide a path to ground for the driver door lock switch signal circuit to the body control module (BCM) through a 470 ohm resistor when the door lock switch is activated to the lock position. This input is used by the BCM to control the door locks.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3270 Door Lock Switch Circuit

Conditions for Setting the DTC

The BCM detects a short to ground through 470 ohms of resistance in the driver door lock switch signal circuit for greater than 60 seconds.

Action Taken When the DTC Sets
    • The BCM stores DTC B3270 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 through 470 ohms of resistance 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 DTC B3270 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • A door lock switch intermittently shorted to ground through the 470 ohm resistor may cause the intermittent malfunction to occur.

Test Description

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

  1. Determines whether the DTC is current or intermittent.

  1. Determines whether the driver or front passenger 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

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, monitor the DTC Information for DTC B3270 in the body control module (BCM).

Does the scan tool indicate that DTC B3270 is current?

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect the driver door lock switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to clear the DTCs.
  5. Operate the vehicle within normal operating conditions.

Does the DTC reset?

Go to Step 4

Go to Step 5

4

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

Did you complete the replacement?

Go to Step 6

--

5

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

Did you complete the replacement?

Go to Step 6

--

6
  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