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B3140




DTC B3140 or B3150

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC B3140 02
- Unlock Switch Circuit Short to Ground

DTC B3150 02
- Lock Switch Circuit Short to Ground

Diagnostic Fault Information





Circuit/System Description

The front passenger door lock switch is wired to the passenger door module (PDM). The lock switch receives a constant ground source. There are 2 signal circuits, one for lock signal, and one for unlock signal. When the switch is activated for a lock or unlock function, the normally open switch contacts for that function are closed and provide a switched ground signal to the PDM.

The driver door lock switch is connected to the driver window switch. The lock switch receives a constant ground. There are 2 signal circuits, one for lock signal, and one for unlock signal. When the switch is activated for a lock or unlock function, the normally open switch contacts for that function are closed and provide a switched ground signal to the driver window switch. These switch activations are detected and processed by the driver window switch and then communicated to the driver door module (DDM) via a serial data message.

Conditions for Running the DTC

The system voltage is 9-16 volts.

Conditions for Setting the DTC

B3140 02

The driver window switch or PDM detects a short to ground on the door unlock signal circuit.

B3150 02

The driver window switch or PDM detects a short to ground on the door lock signal circuit.

Action Taken When the DTC Sets

The driver window switch or the PDM will ignore the input from the associated door lock switch.

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 Latch Description and Operation (Description and Operation)
* Power Door Locks Description and Operation (Description and Operation)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

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

Circuit/System Verification

Ignition ON, observe the scan tool Door Lock Switch parameter while using the driver and passenger door lock switches. The parameter should change from Idle to Lock and Unlock.

Circuit/System Testing

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

If not the specified value, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the driver window switch or PDM.

* Unlock signal circuit terminal E
* Lock signal circuit terminal D

3. Install a 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool Door Lock Switch 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 driver window switch or PDM.

4. Install a 3A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool Door Lock Switch 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 driver window switch or PDM.

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

Component Testing

1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Test for infinite resistance between the signal terminal D and the ground terminal C with the switch in the idle position.

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

3. Test for infinite resistance between the signal terminal E and the ground terminal C with the switch in the idle position.

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

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

If greater than the specified value, replace the door lock switch.

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

If greater than the specified value, replace the 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 Driver Window Switch or PDM replacement, setup, and programming