B3140

DTC B3140, B3145, B3150, or B3155

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* 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 Unlock Switch Circuit

DTC B3145 00
- Passenger Unlock Switch Circuit

DTC B3150 00
- Driver Lock Switch Circuit

DTC B3155 00
- Passenger Lock Switch Circuit

Diagnostic Fault Information






Circuit/System Description

The body control module (BCM) supplies and monitors a reference voltage to the door lock switch through the door lock switch lock/unlock signal circuit. The door lock 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 0.0 volts on the signal circuit.

Conditions for Running the DTC

The system voltage is 9-18 volts.

Conditions for Setting the DTC

B3140 00 or B3150 00

The BCM detects a short to ground in the driver door lock switch lock or unlock signal circuits.

B3144 00 or B3155 00

The BCM detects a short to ground in the passenger door lock switch lock or unlock signal circuits.

Action Taken When the DTC Sets

* The BCM stores the DTC to memory.
* The power door locks will not operate.

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.

Circuit/System Verification

Ignition ON, observe the scan tool Driver Door Lock Sw, Driver Door Unlock Sw, Passenger Door Lock Sw and Passenger Door Unlock Sw parameters while using the driver and passenger door lock switches. The readings should change from Inactive to Active.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Ignition ON, verify the appropriate scan tool Door Lock Sw parameter is Inactive.

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

3. Verify the appropriate scan tool Door Unlock Sw parameter is Inactive.

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

4. If all circuits test normal, test or replace the appropriate door lock switch.

Component Testing

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

• If less than infinite resistance, replace the applicable door lock switch.

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

• If greater than 2 ohms, replace the applicable door lock switch.

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

• If greater than 2 ohms, replace the applicable door lock switch.

Repair Instructions

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

* Door Lock Switch Replacement