B3140

DTC B3140 or B3150

Diagnostic Instructions

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

DTC Descriptors
DTC B3140 00
- Driver Unlock Switch Circuit

DTC B3150 00
- Driver Lock Switch Circuit

Diagnostic Fault Information





Circuit/System Description

The body control module (BCM) monitors the voltage level of the door lock and door unlock signal circuits. When the central door lock switch is in the open position, the voltage level in the signal circuit will be near 12 V. When the central door lock switch is pressed to the lock or unlock position, the voltage level in the appropriate signal circuit will drop to 0V and the BCM will detect the voltage drop and command the door latches to perform the requested lock or unlock command.

Conditions for Running the DTC

The system voltage is 9-16 V.

Conditions for Setting the DTC

B3140 00

The BCM detects short to ground in the unlock signal circuit for greater than 60 seconds.

B3150 00

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

Action Taken When the DTC Sets

The door lock switch will malfunction.

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.

Reference Information
Schematic Reference

Door Lock/Indicator Schematics (Door Lock/Indicator Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Power Door Locks Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool BCM Central Door Lock Switch on Console parameter. The reading should be Inactive and change to Lock and Unlock when pushing the appropriate switch.

Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the A20 radio/HVAC control.
2. Ignition ON, verify the scan tool Central Door Lock Switch on Center Console parameter is Inactive.

• If the value is Lock, test the signal circuit terminal 12 for a short to ground. If the circuit tests normal, replace the K9 BCM.
• If the value is Unlock, test the signal circuit terminal 13 for a short to ground. If the circuit tests normal, replace the K9 BCM.

3. If all circuits test normal, replace the A20 radio/HVAC control.

Repair Instructions

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

Control Module References (Programming and Relearning) for BCM and HVAC control replacement, setup and programming