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 body control module (BCM) supplies a 12 V signal to the key switch lock and unlock signal circuits. When the key is inserted into the driver door key cylinder and turned to the Unlock or Lock position, a switch within the driver door latch closes causing the voltage to drop to 0 V within the appropriate key switch signal circuit. The BCM will detect the drop in voltage and will command all the doors to unlock or lock.
Reference Information
Schematic Reference
Door Lock/Indicator Schematics Door Lock/Indicator Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
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 Control Module References for scan tool information
Circuit/System Verification
Ignition ON, insert the key into the drivers door lock key cylinder, turn the key to the LOCK position and then to the UNLOCK position while observing the driver and passenger doors. All doors should perform the LOCK and UNLOCK functions.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the A23D door latch assembly-driver.
2. Test for less than 10 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, test for greater than 9 V between the signal circuit terminal 4 and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
4. Test for greater than 9 V between the signal circuit terminal 9 and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
5. If all circuits tests normal, test or replace the A23D door latch assembly-driver.
Component Testing
1. Ignition OFF, disconnect the harness connector at the A23D door latch assembly-driver.
2. Test for infinite resistance between the signal terminal 4 and the ground terminal 8 with the switch in the open position.
• If not the specified value, replace the A23D door latch assembly-driver.
3. 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 A23D door latch assembly-driver.
4. Test for less than 2 ohms between the signal terminal 4 and the ground terminal 8 with the switch in the Lock position.
• If greater than the specified range, replace the A23D door latch assembly-driver.
5. Test for less than 2 ohms between the signal terminal 9 and the ground terminal 8 with the switch in the Unlock position.
• If greater than the specified range, replace the A23D door latch assembly-driver.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Front Side Door Latch Replacement Service and Repair
* Control Module References Control Module References for BCM replacement, programming and setup