The driver door key switch is contained within the driver door latch. The driver door key cylinder switch contacts, which are normally open. When the door key is turned to unlock, the switch contacts close and the driver door module (DDM) detects a switched ground. The DDM sends a message via serial data to the remote control door lock receiver (RCDLR), indicating the key cylinder unlock switch request. The RCDLR is the master of all lock and unlock operations. If the RCDLR determines that the key cylinder unlock switch request is valid and conditions are correct for the door modules to perform the unlock function, it sends a message via serial data back to all door modules to unlock all doors.

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information.

1. Ignition ON, command the doors to LOCK and UNLOCK by using the driver door lock switch, all doors should perform the LOCK and UNLOCK functions.

⇒	If any door fails to LOCK or UNLOCK, refer to Power Door Locks Malfunction.

2. Observe the scan tool Door Cylinder Switch parameters while the turning and holding the key in the driver door lock cylinder to the left and then to the right, parameter should change from Idle to Unlock.

1. Ignition OFF, disconnect the harness connector at the driver door latch.
2. Test for less than 10 ohms between the ground circuit terminal listed below and ground.

•	Right hand drive terminal 3

•	Left hand drive terminal 8

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Door Cylinder Switch parameter is Idle.

⇒	If not the specified value, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the DDM.

•	Right hand drive terminal 4

•	Left hand drive terminal 9

4. Install a 3A fused jumper wire between the signal circuit terminal listed below and the ground. Verify the scan tool Door Cylinder Switch parameter is Unlock.

•	Right hand drive terminal 4

•	Left hand drive terminal 9

⇒	If not one of the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the DDM.

5. If all circuits test normal, test or replace the driver door latch.

1. Ignition OFF, disconnect the harness connector at the driver door latch.
2. Test for infinite resistance between the terminals listed below with the switch in the Idle position.

•	Right hand drive terminals 4 and 3

•	Left hand drive terminals 9 and 8

⇒	If not the specified value, replace the driver door latch.

3. Test for less than 2 ohms between the terminals listed below with the switch in the Unlock position.

•	Right hand drive terminals 4 and 3

•	Left hand drive terminals 9 and 8

⇒	If greater than the specified range, replace the driver door latch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.