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 switch contains a signal circuit and a low reference circuit. When the door key is turned to unlock, the switch contacts, which are normally open, close and the driver door module (DDM) detects a switched ground. The DDM sends a message via serial data message to the passenger door module (PDM), and body control module (BCM) to unlock their respective 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 (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
1. Ignition ON, observe the door locks while commanding the doors to LOCK and UNLOCK with a scan tool, all doors should perform the LOCK and UNLOCK functions.
• If any door fails to LOCK or UNLOCK, refer to Power Door Locks Malfunction (Power Door Locks Malfunction).
2. Insert the key into the driver's door lock cylinder, turn the key to the unlock position and hold for greater than 1 second while observing the scan tool Door Key Cyl Unlock Switch parameter, the parameter should change between Idle and Unlock.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the driver door latch.
2. Ignition ON, test for less than 10 ohm between the low reference circuit terminal 8 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance.
3. Verify the scan tool Door Key Cyl. Unlock 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 DDM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 9 and the low reference circuit terminal 8. Verify the scan tool Door Key Cyl. Unlock 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 DDM.
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 low reference terminal 8 with the switch in the Idle position.
• If not the specified value, replace the driver door latch.
3. Test for less than 2 ohm between the signal terminal 9 and the low reference terminal 8 with the switch in the unlock 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 Latch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for DDM replacement, setup, and programming