Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Driver Door Key Switch Lock Signal | 1 | 1 | 1 | -- |
Driver Door Key Switch Unlock Signal | 1 | 1 | 1 | -- |
Ground | -- | 1 | 1 | -- |
1. Key Cylinder Switch Inoperative | ||||
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.
Reference Information
Schematic Reference
Door Lock/Indicator Schematics
Connector End View Reference
Description and Operation
Power Door Locks Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
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 parameter should change from Idle to Lock and Unlock.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the driver door lock switch.
- Test for less than 1 ohm between the ground circuit terminal 8 and ground.
- Ignition ON, verify the scan tool LF Key Cylinder Lock Switch parameter is Idle.
- Install a 3-amp fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool LF Key Cylinder Lock Switch parameter is Lock.
- Install a 3-amp fused jumper wire between the signal circuit terminal 9 and ground. Verify the scan tool LF Key Cylinder Lock Switch parameter is Unlock.
- If all circuits tests normal, test or replace the driver door lock.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the signal circuit terminal 4 or 9 for a short to ground. If the circuits test normal, replace the BCM. |
| ⇒ | 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 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. |
Component Testing
- Ignition OFF, disconnect the harness connector at the driver door lock.
- Test for infinite resistance between the signal terminal 4 and the ground circuit terminal 8 with the switch in the open position.
- Test for infinite resistance between the signal terminal 9 and the ground circuit terminal 8 with the switch in the open position.
- Test for less than 2 ohms between the signal terminal 9 and the ground circuit terminal 8 with the switch in the Unlock position.
- Test for less than 2 ohms between the signal terminal 8 and the ground circuit terminal 8 with the switch in the Lock position.
| ⇒ | If not the specified value, replace the driver door lock. |
| ⇒ | If not the specified value, replace the driver door lock. |
| ⇒ | If greater than the specified range, replace the driver door lock. |
| ⇒ | If greater than the specified range, replace the driver door lock. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
