Power Door Lock Key Cylinder Switches Malfunction

Power Door Lock Key Cylinder Switches Malfunction

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.

Diagnostic Fault Information






Circuit/System Description

The key cylinder unlock feature will unlock or lock all of the doors when the body control module (BCM) receives a Key Unlock Switch or an Key Lock Switch signal for greater than 1 second and will unlock or lock all of the doors.

Reference Information
Schematic Reference

Door Lock/Indicator Schematics Door Lock/Indicator Schematics
Connector End View Reference

Component Connector End Views Connector End Views By Name
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 Relearningfor scan tool information

Circuit/System Verification

Ignition ON, insert the key into the driver door lock cylinder, turn the key to the LOCK position and turn the key to the UNLOCK position while observing the scan tool Door Cylinder Switch parameter, the parameter should change from Idle to Lock and Unlock.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the driver door latch.
2. Test for less than 5 ohm between the ground circuit terminal 8 and ground.

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

3. Ignition ON, verify the scan tool Door Cylinder Switch parameter is Idle.

• If not the specified value, test the signal circuit terminal 9 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3 A fused jumper wire between the signal circuit terminal 9 and ground. Verify the scan tool Door Cylinder 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 BCM.

5. If all circuits test normal, test or replace the driver door latch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the driver door latch.
2. Test for infinite resistance between the signal terminal 9 and the ground terminal 8 with the switch in the open position.

• If not the specified value, replace the driver door latch.

3. Test for 450-550 ohm between the signal terminal 9 and the ground terminal 8 with the switch in the unlock position.

• If not the specified range, replace the driver door latch.

4. Test for less than 2 ohm between the signal terminal 9 and the ground terminal 8 with the switch in the lock position.

• If greater than the specified range, replace the driver door latch.

Repair Instructions

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

* Front Side Door Lock Replacement Front Side Door Lock Replacement
* Control Module References Programming and Relearningfor BCM replacement, setup and programming