Diagnostic Instructions
Circuit/System Description
The key cylinder lock/unlock feature will unlock or lock all of the doors when the body control module (BCM) receives a Door Lock Key Switch Unlock or Lock signal for greater than 1 second and will unlock or lock all of the doors and the liftgate.
Reference Information
Schematic Reference
Door Lock/Indicator Schematics
Connector End View Reference
Vehicle Access Connector End Views
Description and Operation
Power Door Locks Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition OFF, insert the key into the driver 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. Observe the scan tool LF Key Cylinder Lock Switch
parameters, the reading should change between Lock and Unlock.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the Driver Door Key Switch.
- Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit terminal C and ground.
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
- Ignition ON, verify the scan tool LF Key Cylinder Lock Switch parameter is Idle.
⇒ | If not the specified value, test the signal circuit terminal A or D for a short to ground. If the circuits test normal, replace the BCM. |
- Install a 3-amp fused jumper wire between the signal circuit terminal A and ground, verify the scan tool LF Key Cylinder 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 BCM. |
- Install a 3-amp fused jumper wire between the signal circuit terminal D and ground, verify the scan tool LF Key Cylinder 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 BCM |
- If all circuits tests normal, test or replace the Driver Door Key Switch.
Component Testing
- Ignition OFF, disconnect the harness connector at the Driver Door Key Switch.
- Test for infinite resistance between the signal terminal A and the ground circuit terminal C with the switch in the open position.
⇒ | If not the specified value, replace the Driver Door Key Switch. |
- Test for infinite resistance between the signal terminal D and the ground circuit terminal C with the switch in the open position.
⇒ | If not the specified value, replace the Driver Door Key Switch. |
- Test for less than 2.0 ohms between the signal terminal D and the ground circuit terminal C with the switch in the Unlock position.
⇒ | If greater than the specified range, replace the Driver Door Key Switch. |
- Test for less than 2.0 ohms between the signal terminal A and the ground circuit terminal C with the switch in the Lock position.
⇒ | If greater than the specified range, replace the Driver Door Key Switch. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.