B3145

DTC B3140, B3145, B3150, or B3155

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B3140
- Driver Unlock Switch Circuit

DTC B3145
- Passenger Unlock Switch Circuit

DTC B3150
- Driver Lock Switch Circuit

DTC B3155
- Right Front Lock Switch Circuit

Diagnostic Fault Information






Circuit/System Description

The power door lock switch signal circuits are referenced from battery voltage by the body control module (BCM). When a switch is pressed to the lock or unlock position the appropriate signal circuit is grounded. When a signal circuit is grounded the reference voltage goes low indicating to the BCM that the corresponding switch is active.

Conditions for Running the DTC

Battery voltage is between 9-16 volts.

Conditions for Setting the DTC

A door lock or unlock switch input to the BCM is active for greater than 60 seconds.

Action Taken When the DTC Sets

The input signal will be ignored by the BCM for as long as the code is current.

Conditions for Clearing the DTC

* When the input signal has inactive for 2.5 seconds the DTC will be a history status code.
* The history code will clear after 50 fault-free ignition cycles or by using the scan tool clear DTCs feature.

Diagnostic Aids

A current switch code indicates that the switch is stuck or the signal circuit is shorted to ground.

Circuit/System Verification

Observe the scan tool door lock and unlock switch parameters while operating the switch to the lock and unlock positions. The readings should change from inactive to active.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the door lock switch.
2. Test for less than 1 ohm of resistance between the ground circuit terminal B and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Verify the scan tool door lock and unlock switch parameters are inactive.

• If not the specified value, test the signal circuit listed below for a short to ground. If the circuit tests normal, replace the BCM.

* Lock terminal D
* Unlock terminal E

4. Install a 3A fused jumper wire between the signal circuits listed below and the ground circuit terminal B. Verify the scan tool door lock and unlock switch parameters are active.

* Lock terminal D
* Unlock terminal E

• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the door lock switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the door lock switch.
2. Test for infinite resistance between the signal terminal listed below and the ground terminal B with the switch in the open position.

* Lock terminal D
* Unlock terminal E

• If not the specified value, replace the door lock switch.

3. Test for less than 1 ohm between the signal terminal listed below and the ground terminal B with the switch in the closed position.

* Lock terminal D
* Unlock terminal E

• If greater than the specified range, replace the door lock switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Door Lock and Side Window Switch Replacement - Driver Side
* Door Lock and Side Window Switch Replacement - Passenger Side
* Control Module References for BCM replacement, programming, and setup Programming and Relearning