B3140
Power Door Lock Switch Malfunction - 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 Door Unlock Switch Circuit
DTC B3150 00
- Left Front Door 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 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 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
B3140 00
The BCM will ignore the unlock signal and the doors will not unlock when using the central door lock switch.
B3150 00
The BCM will ignore the lock signal and the doors will not lock when using the central 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
* Radio/Navigation System Schematics Radio/Navigation System Schematics
Connector End View Reference
Component Connector End Views Connector End Views By Name
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify the scan tool BCM Central Door Lock Switch on Console parameter changes from Inactive to Lock and Unlock when pushing the appropriate switch on the central door lock switch.
• If the parameter does not change
Refer to Circuit/System Testing.
• If the parameter changes
3. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness connector at the A20 radio/HVAC control. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohm between the ground circuit terminal 17 and ground.
• If 10 ohm or greater
1. Ignition OFF.
2. Test for less than 2 ohm in the ground circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, repair the open/high resistance in the ground connection.
• If less than 10 ohm
3. Ignition ON.
4. Verify the scan tool BCM Central Door Lock Switch on Console parameter is Inactive.
• If the value is Lock
1. Ignition OFF, disconnect the harness connector at the K9 BCM.
2. Test for infinite resistance between the signal circuit terminal 19 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K9 BCM.
• If the value is Unlock
1. Ignition OFF, disconnect the harness connector at the K9 BCM.
2. Test for infinite resistance between the signal circuit terminal 15 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K9 BCM.
• If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 13 and the ground circuit terminal 17.
6. Verify the scan tool BCM Central Door Lock Switch on Console parameter is Unlock.
• If not Unlock
1. Ignition OFF, disconnect the harness connector at the K9 BCM, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohm in the signal circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, replace the K9 BCM.
• If Unlock
7. Install a 3 A fused jumper wire between the signal circuit terminal 12 and the ground circuit terminal 17.
8. Verify the scan tool BCM Central Door Lock Switch on Console parameter is Lock.
• If not Lock
1. Ignition OFF, disconnect the harness connector at the K9 BCM, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohm in the signal circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, replace the K9 BCM.
• If Lock
9. Test or replace the A20 radio/HVAC control.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Radio Control Assembly Replacement Radio Control Assembly Replacement
* Control Module References Control Module References for BCM replacement, programming and setup