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DTC B3140 or B3150

DTC B3140 or B3150

Diagnostic Instructions


• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• 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 00

Driver's door unlocking switch circuit

DTC B3150 00

Locking switch circuit, door, left front

Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Driver's door, door lock button, locking signal B3150 00 1 1 -
Driver's door, door lock button, unlocking signal B3140 00 2 2 -
Radio/HVAC, check ground - 3 - -
1. Faulty door lock switch 2. Faulty door unlocking switch 3. Faulty door lock and unlocking switch


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 0 V. When the central door lock switch is pressed to the lock or unlock position, a signal will be sent to the BCM requesting a 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

BCM will ignore the unlocking signal and the doors will not unlock when using the central locking button.

B3150 00

BCM will ignore the locking signal and the doors will not lock when using the central locking button.

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

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference


• Circuit Testing

• Connector Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs


Scan Tool Reference

Control Module References 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 harness connector at the A20 radio/HVAC control.

2. Test for less than 5 Ω between the ground circuit pin 17 and ground.

3. If the value exceeds the specified range, test the ground circuit for open/high resistance.

4. Ignition ON, verify the scan tool Central Door Lock Switch on Center Console parameter is Inactive.

5. 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.

6. 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.

7. Fit a 3 A fuse-protected jumper cable between the signal circuit pin 12 and ground. Verify that the diagnostic tool parameter "Central locking button in the center console" is Locked.

8. If not the specified value, test the signal circuit for short to voltage or open/high resistance. If the circuit tests normal, replace K9 BCM.

9. Fit a 3 A fuse-protected jumper cable between the signal circuit pin 13 and ground. Verify that the diagnostic tool parameter "Central locking button in the center console" is Unlocked.

10. If not the specified value, test the signal circuit for short to voltage or open/high resistance. If the circuit tests normal, replace K9 BCM.

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


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM and HVAC control replacement, setup and programming