Power Door Lock Key Cylinder Switches Inoperative

Power Door Lock Key Cylinder Switches Inoperative

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.



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 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 OFF, insert the key into the drivers door lock cylinder, turn the key clockwise and hold for greater than 1 second and turn the key counterclockwise and hold for greater than 1 second 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 assembly.
2. Test for less than 5 ohms 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 parameter, test the signal circuit terminal 9 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3-amp 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 parameter, 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 assembly.



Component Testing

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

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

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

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

4. Test for less than 2.0 ohms between the signal terminal 9 and the ground circuit terminal 8 with the switch in the lock position.

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




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 Relearning) for BCM replacement, setup and programming