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 | -- |
Driver Door Key Switch 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 and the liftgate.
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 ON, insert the key into the drivers door lock cylinder, turn the key to the LOCK position and then to the UNLOCK positon while observing the scan tool LF Key Cylinder Lock Switch parameter. The parameter should change between Idle, Lock and Unlock.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the driver door key switch.
- Test for less than 1 ohm between the ground circuit terminal C and ground.
- Ignition ON, verify the scan tool LF Key Cylinder Lock Switch parameter is Idle.
- Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool LF Key Cylinder Lock Switch parameter is Lock.
- Install a 3A fused jumper wire between the signal circuit terminal D 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 key switch.
| ⇒ | 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 listed below for a short to ground. If the circuits test normal, replace the BCM. |
| • | Signal circuit terminal A |
| • | Signal circuit terminal D |
| ⇒ | 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 key switch.
- Test for infinite resistance between the signal terminal A and the ground terminal C with the switch in the open position.
- Test for infinite resistance between the signal terminal D and the ground terminal C with the switch in the open position.
- Test for less than 2 ohms between the signal terminal D and the ground terminal C with the switch in the Unlock position.
- Test for less than 2 ohms between the signal terminal A and the ground terminal C with the switch in the Lock position.
| ⇒ | If not the specified value, replace the driver door key switch. |
| ⇒ | If not the specified value, replace the driver door key switch. |
| ⇒ | If greater than the specified range, replace the driver door key switch. |
| ⇒ | If greater than the specified range, replace the driver door key switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
