B3140
DTC B3140, B3145, B3150, or B3155
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 B3145 00
- Passenger Unlock Switch Circuit
DTC B3150 00
- Driver Lock Switch Circuit
DTC B3155 00
- Right Front Lock Switch Circuit
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) supplies a 12 V signal to each of the door lock and door unlock signal circuits. When the door lock switches are in the open position, the voltage level in the signal circuit will be near 12 V. When any door lock switch is pressed to the lock or unlock position, the voltage level in the appropriate signal circuit will drop to 0 V 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 must be between 9-16 V.
Conditions for Setting the DTC
B3140 00
The BCM detects short to ground in the driver unlock signal circuit for greater than 60 seconds.
B3145 00
The BCM detects short to ground in the passenger unlock signal circuit for greater than 60 seconds.
B3150 00
The BCM detects a short to ground in the driver lock signal circuit for greater than 60 seconds.
B3155 00
The BCM detects a short to ground in the passenger lock signal circuit for greater than 60 seconds.
Action Taken When the DTC Sets
B3140 00
The BCM will ignore the unlock signal and the doors will not unlock when using the driver door unlock switch.
B3145 00
The BCM will ignore the unlock signal and the doors will not unlock when using the passenger door unlock switch.
B3150 00
The BCM will ignore the lock signal and the doors will not lock when using the driver door lock switch.
B3155 00
The BCM will ignore the lock signal and the doors will not lock when using the passenger door lock switch.
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 A/C Compressor Clutch
Description and Operation
Power Door Locks Description and Operation (-AXE) Power Door Locks Description and Operation (-AXE)Power Door Locks Description and Operation (AXE) Power Door Locks Description and Operation (AXE)
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 Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool Driver Door Lock Sw, Psgr Door Lock Sw, Driver Door Unlock Sw and Psgr Door Unlock Sw. parameters while using the appropriate door lock switch. The reading should change between Inactive and Active.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Ignition ON, verify the scan tool Door Lock Sw. parameter is Inactive.
• If not the specified value, test the signal circuit terminal E for a short to ground. If the circuit tests normal, replace the BCM.
3. Verify the scan tool Door Unlock Sw parameter is Inactive.
• If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, test or replace the door lock switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Test for infinite resistance between the signal terminals D and E and the ground terminal B with the switch in the open position.
• If less than the specified value, replace the door lock switch.
3. Test for less than 2 ohms between the signal terminal D and the ground terminal B with the switch in the unlock position.
• If greater than the specified range, replace the door lock switch.
4. Test for less than 2 ohms between the signal terminal E and the ground terminal B with the switch in the lock position.
• If greater than the specified range, replace the door lock switch
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Door Lock Switch Replacement - Driver Side Service and Repair
* Door Lock Switch Replacement - Passenger Front (Traverse)
* Control Module References Control Module References for BCM replacement, programming and setup