Operation

OPERATION

The Wireless Control Module (WCM), commonly referred to as the Sentry Key Remote Entry Module (SKREEM), uses transponders (trigger modules) located in the front wheel wells on the vehicle to provide it with the location of the front tire pressure sensors on the vehicle. Like the base system, the WCM receives RF signals from all four rotating wheel speed sensors. When the WCM needs to know which sensor is located at a particular location on the vehicle, it directs the transponder at that location to send out a low frequency signal to excite the nearby sensor. The WCM then receives that excited signal and knows where that sensor is located. This auto-locating process only happens in the first 10 minutes of any WCM cycle while traveling at speeds above 20 mph (32 km/h) (Each WCM cycle ends when the vehicle has been shut off for a time period of approximately 20 minutes or longer). If the TPMS fails to localize, the TPM indicator lamp will flash on/off for 75 seconds, and remain on solid.