B3150

DTC B3140 or B3150

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 BCM supplies and monitors a reference voltage to the door lock/window switch through the door lock switch lock and unlock signal circuits. The door lock/window switch also receives a constant ground source. If a door lock switch is placed in the lock position or unlock position, the reference voltage is taken directly to ground and the BCM detects the voltage drop on the signal circuit.


Conditions for Running the DTC

The system voltage is 9 - 16 volts.


Conditions for Setting the DTC

B3140 00

The BCM detects a fault in the unlock switch signal circuit.

B3150 00

The BCM detects a fault in the lock switch signal circuit


Action Taken When the DTC Sets

The power door locks 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 become 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 (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

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


Circuit/System Verification

Ignition ON, observe the scan tool Driver Door Lock Sw. and Driver Door Unlock Sw. parameters while using the door lock switch. The parameter should change between Inactive and Active when changing between the commanded states.


Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the door lock/window switch.
2. Test for less than 20 ohm between the ground circuit terminal 4 and ground.

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

3. Ignition ON, verify the scan tool Driver Door Lock Sw. parameter is Inactive.

• If not the specified value, test the signal circuit terminal 15 for a short to ground. If the circuit tests normal, replace the BCM.

4. Verify the scan tool Driver Door Unlock Sw. parameter is Inactive.

• If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the BCM.

5. Install a 3A fused jumper wire between the signal circuit terminal 15 and ground. Verify the scan tool Driver Door Lock Sw. parameter is Active.

• 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 BCM.

6. Install a 3A fused jumper wire between the signal circuit terminal 5 and ground. Verify the scan tool Driver Door Unlock Sw. parameter is Active.

• 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 BCM.

7. If all circuits test normal, test or replace the door lock/window switch.



Component Testing

1. Ignition OFF, disconnect the X2 harness connector at the door lock window/switch.
2. Test for infinite resistance between the signal terminals 5 and 15 and the ground terminal 4 with the switch in the open position.

• If less than the specified value, replace the door lock/window switch.

3. Test for less than 2 ohm between the signal terminal 15 and the ground terminal 4 with the switch in the lock position.

• If greater than the specified range, replace the door lock/window switch.

4. Test for less than 2 ohm between the signal terminal 5 and the ground terminal 4 with the switch in the unlock position.

• If greater than the specified value, replace the door lock/window switch




Repair Instructions

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

* Power Mirror Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming