Diagnostic Procedure

*DRIVER DOOR KEY FAILS TO ARM OR TO DISARM VTSS

Test	Action
1	With the DRBIII® in Sensors, read the DRV DOOR ARM/DISARM SW voltage. Note: The voltage measurements are not the same for the driver and passenger lock cylinders. Rotate the Key in the Driver Cylinder Lock to the lock and unlock positions. Does the DRBIII® display 3.5-4.5 volts in the lock position and 6.0-7.0 volts in the unlock position. Yes: Replace and program the Body Control Module. Perform VTSS VERIFICATION TEST - 1A . No: Go To 2
2	Disconnect the Driver Cylinder Lock Switch harness connector Using a 12-volt test light connected to ground, check the Fused B+ circuit. Does the test light illuminate? Yes: Go To 3 No: Repair the Driver Cylinder Lock Switch Fused B+ circuit for an open. Perform VTSS VERIFICATION TEST - 1A .
3	Disconnect the Body Control Module C4 harness connector. Disconnect the Driver Cylinder Lock Switch harness connector. Using a 12-volt Test Light connected to 12-volts, check the Driver Cylinder Lock Switch MUX circuit. Does the test light illuminate? Yes: Repair the Driver Cylinder Lock Switch MUX circuit for a short to ground. Perform VTSS VERIFICATION TEST - 1A . No: Go To 4
4	Disconnect the Body Control Module C4 harness connector. Disconnect the Driver Cylinder Lock Switch harness connector. Measure the resistance of the Driver Cylinder Lock Switch MUX circuit between the Driver Cylinder Lock Switch connector and the BCM C4 connector. Is the resistance below 5.0 ohms? Yes: Replace the Driver Cylinder Lock Switch in accordance with the Service Information. Perform VTSS VERIFICATION TEST - 1A . No: Repair the Driver Cylinder Lock Switch MUX circuit for an open. Perform VTSS VERIFICATION TEST - 1A .