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 |
|---|---|---|---|---|
Key Lock Switch Signal | 1 | 1 | 1 | -- |
Key Unlock Switch Signal | 1 | 1 | 1 | -- |
Driver Door Latch Ground | -- | 1 | 1 | -- |
1. Key Cylinder Switch Malfunction. | ||||
Circuit/System Description
The key cylinder unlock feature will lock and unlock all of the doors when the body control module (BCM) receives a Key Lock Switch signal or a Key Unlock Switch signal for greater than 1 second and will lock or unlock 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’s door lock cylinder, turn the key to the LOCK position and hold for greater than 1 second and turn the key to the UNLOCK position and hold for greater than 1 second, all doors should LOCK and UNLOCK while changing between the commanded states.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the driver door latch assembly.
- Test for less than 1 ohm between the ground circuit terminal 8 and ground.
- Test for greater than 9 volts between the signal circuit terminals listed below and ground:
- Connect a 3A fused jumper wire between the signal circuit terminal 4 and ground. Verify the doors perform the LOCK function.
- Connect a 3A fused jumper wire between the signal circuit terminal 9 and ground. Verify the doors perform the UNLOCK function
- If all circuits tests normal, test or replace the driver door latch assembly.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| • | Unlock signal circuit terminal 9 |
| • | Lock signal circuit terminal 4 |
| ⇒ | 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 BCM |
| ⇒ | If the door latches do not LOCK, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM |
| ⇒ | If the door latches do not UNLOCK, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM |
Component Testing
- Ignition OFF, disconnect the harness connector at the driver door latch assembly.
- Test for infinite resistance between the signal terminal 4 and the ground terminal 8 with the switch in the open position.
- Test for infinite resistance between the signal terminal 9 and the ground terminal 8 with the switch in the open position.
- Test for less than 2 ohms between the signal terminal 9 and the ground terminal 8 with the switch in the Unlock position.
- Test for less than 2 ohms between the signal terminal 4 and the ground terminal 8 with the switch in the Lock position.
| ⇒ | If not the specified value, replace the driver door latch assembly. |
| ⇒ | If not the specified value, replace the driver door latch assembly. |
| ⇒ | If greater than the specified range, replace the driver door latch assembly. |
| ⇒ | If greater than the specified range, replace the driver door latch assembly. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
