Volt

DTC B3140 or B3150

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.

The system voltage is 9-16 V.

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.

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.

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

Scan Tool Reference

Control Module References for scan tool information

Vehicle in Service Mode, 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 on the central door lock switch.

1. Vehicle OFF, disconnect the harness connector at the A20 radio/HVAC control.
2. Test for less than 10 Ω between the ground circuit terminal 17 and ground.

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

3. Vehicle in Service Mode, verify the scan tool Central Door Lock Switch on Centre 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.

4. Install a 3 A fused jumper wire between the signal circuit terminal 12 and ground. Verify the scan tool Central Door Lock Switch on Center Console parameter is Lock.

⇒	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 K9 BCM.

5. Install a 3 A fused jumper wire between the signal circuit terminal 13 and ground. Verify the scan tool Central Door Lock Switch on Centre Console parameter is Unlock.

⇒	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 K9 BCM.

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

1. Vehicle OFF, disconnect the harness connector at the A20 radio/HVAC control.
2. Test for infinite resistance between the signal terminal 13 and the ground terminal 17 with the switch in the open position.

⇒	If not the specified value, replace the A20 radio/HVAC control.

3. Test for infinite resistance between the signal terminal 12 and the ground terminal 17 with the switch in the open position.

⇒	If not the specified value, replace the A20 radio/HVAC control.

4. Test for less than 2 Ω between the signal terminal 12 and the ground terminal 17 with the switch in the lock position.

⇒	If greater than the specified range, replace the A20 radio/HVAC control.

5. Test for less than 2 Ω between the signal terminal 13 and the ground terminal 17 with the switch in the unlock position.

⇒	If greater than the specified range, replace the A20 radio/HVAC control.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.