Diagnose and fix a Chrysler, Ram, Jeep no start
A Chrysler, Ram and Jeep no start is often caused by a locked Wireless control module. Chrysler vehicles use a wireless control module (WCM) referred to as the Sentry key Remote Entry Module (SKREEM). This module is extremely sensitive to static discharge that can occur during dry or cold winter months when sliding across the seats. When that happens, The WCM lock up and you get a no start condition. This will also disable the remote lock/unlock feature of your key fob. Chrysler has issued an updated WCM that is less susceptible to static lockup.
Diagnose WCM lockup with a scan tool
If you have access to a live data scan tool, you can confirm WCM lockup by turning the IGN switch to on and looking at the status of the bus. If the WCM is locked up, you will see an “off bus” message.
Reset the WCM
The ultimate fix is to replace the WCM with the updated version. But you can reset the locked up WCM by temporarily removing the IOD fuse. Turn the IGN off and remove the key. Remove the IOD fuse and leave it out for at least 10-seconds. Then reinstall the IOD fuse. The vehicle should now start.
Vehciles affected by locked up WCM
2006-’08 Chrysler PT Cruiser (PT)
2007-’08 Ram Truck (1500/2500/3500/ 4500/5500) (DR/DH/D1/DC/DM)
Sebring (China) (J1)
2008 Liberty/Cherokee (KK)