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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 body control module (BCM) controls the door lock, passenger door unlock and driver door unlock relays. Voltage is applied to the appropriate relay through the door lock/unlock control circuit when the BCM senses a door lock/unlock switch activation or a keyless entry lock or unlock command.

Conditions for Running the DTC

The system voltage must be between 9-16 volts.

Conditions for Setting the DTC

B3140 00

The BCM detects a fault in the left unlock switch signal circuits.

B3150 00

The BCM detects a fault in the left lock switch signal circuits.

Action Taken When the DTC Sets

The driver door lock switch 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 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 (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 Rear Doors Lock Cmd and Rear Doors Unlock Cmd parameters while using the driver door lock switch. The parameter should change between On and Off when changing between the commanded states.

Circuit/System Testing

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

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

3. Ignition ON, verify the scan tool Rear Doors Lock Cmd parameter is Off.

If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.

4. Verify the scan tool Rear Doors Unlock Cmd parameter is Off.

If not the specified value, test the signal circuit terminal 3 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 1 and ground. Verify the scan tool Rear Doors Lock Cmd parameter is On.

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 3 and ground. Verify the scan tool Rear Doors Unlock Cmd parameter is On.

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 driver door lock switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the driver door lock switch.
2. Test for infinite resistance between the signal terminals 3 and 1 and the ground terminal 2 with the switch in the open position.

If less than the specified value, replace the driver door lock switch.

3. Test for less than 2 ohms between the signal terminal 3 and the ground terminal 2 with the switch in the unlock position.

If greater than the specified range, replace the driver door lock switch.

4. Test for less than 2 ohms between the signal terminal 1 and the ground terminal 2 with the switch in the lock position.

If greater than the specified range, replace the driver door lock switch.

Repair Instructions

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

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