Passenger Door Key Fails To Arm Or Disarm VTSS

Possible Causes:

• Fused B+ Open
• Passenger Cylinder Lock Switch MUX Circuit Shorted To Ground
• Passenger Cylinder Lock Switch MUX Circuit Open
• Passenger Cylinder Lock Switch
• BCM - VTSS Won't Arm Or Disarm With Door Key

Testing

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Using scan tool, read PASS DOOR ARM/DISARM SW voltage. Rotate key in passenger cylinder lock switch to lock and unlock positions. If scan tool displays 3.5-4.5 volts in lock position and 6.0-7.0 volts in unlock position, replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. If scan tool does not display 3.5-4.5 volts in lock position and 6.0-7.0 volts in unlock position, go to next step.
2. Disconnect 2-pin passenger cylinder lock switch connector. Connect a 12-volt test light between ground and passenger cylinder lock switch connector terminal No. 2, fused B+ circuit (Pink wire). If test light illuminates, leave passenger cylinder lock switch connector disconnected and go to next step. If test light does not illuminate, repair open in Pink wire.
3. Disconnect BCM connector C4. Connect 12-volt test light between battery voltage and BCM connector C4 terminal No. 3, passenger cylinder lock switch MUX circuit (Dark Green/Orange wire). See Figure . If test light illuminates, repair short to ground in Dark Green/Orange wire. If test light does not illuminate, leave connectors disconnected and go to next step.
4. Measure resistance of passenger cylinder lock switch MUX circuit (Dark Green/Orange wire) between passenger cylinder lock switch terminal No. 1 and BCM connector C4 terminal No. 3. If resistance is less than 5 ohms, replace passenger cylinder lock switch. See POWER DOOR LOCKS & TRUNK RELEASE - CONCORDE, INTREPID & 300M article. If resistance is 5 ohms or more, repair open in Dark Green/Orange wire.