Operation

OPERATION

SENTRY KEY REMOTE ENTRY SYSTEM (SKREES)

The Sentry Key Remote Entry Module (SKREEM), sometimes referred to as the Wireless Control Module (WCM), receives an encrypted Radio Frequency (RF) signal from the transponder key. The SKREEM/WCM then decrypts the signal and broadcasts the requested remote commands to the appropriate modules in the vehicle over the Controller Area Network (CAN) data bus. A valid transponder key ID must be incorporated into the RF signal in order for the SKREEM/WCM to pass the message on to the appropriate modules.

Automatic transponder key synchronization is done by the SKREEM/WCM if a valid transponder key is inserted into the ignition cylinder, and the ignition is turned ON. This provides a maximum operation window for RKE functions.

Each Sentry Key Remote Entry System (SKREES), sometimes referred to as the Sentry Key Immobilizer System (SKIS), consists of a SKREEM/WCM and a transponder key. Each system has a secret key code unique to that system. The secret key is electronically coded in the SKREEM/WCM and in all programmed transponder keys. It is used for immobilization and RKE functions for data security. In addition, each transponder key will have a unique identification.

NOTE: After a SKREEM/WCM is replaced, the ignition/transponder keys need to be programmed to the new SKREEM/WCM. Follow the directions on the diagnostic scan tool. The transponder key for the SKREES/SKIM and the RKE will both be programmed during this operation. There is no need to program the fob of the key for RKE functionality once the transponder key is programmed to the new SKREEM/WCM.

REMOTE KEYLESS ENTRY (RKE)

After pressing the lock button on the RKE transmitter, all of the door locks will lock, the illuminated entry will turn off (providing all doors are closed), and the Vehicle Theft Security System (VTSS) (if equipped) will arm. After pressing the unlock button, on the RKE transmitter, one time, the driver door lock will unlock, the illuminated entry will turn on the courtesy lamps, and the VTSS (if equipped) will disarm. After pressing the unlock button a second time, the remaining door locks will unlock. The Electronic Vehicle Information Center (EVIC) or a scan tool can reprogram this feature to unlock all of the door locks with one press of the unlock button. If the vehicle is equipped with the memory system, the memory message will identify which transmitter (1 or 2) sent the signal. Refer to Overhead Console/Electronic Vehicle Information Center for more information on customer programmable features.

The SKREEM/WCM is capable of retaining up to 8 individual access codes (8 transmitters). If the PRNDL is in any position except park, the SKREEM/WCM will disable the RKE. The 4 button transmitter uses 1-CR2032 battery. The minimum battery life is approximately 4.7 years based on 20 transmissions a day at 84°F (25°C). Use a scan tool or the Miller Tool 9001 RF Detector to test the RKE transmitter. Use a scan tool or the customer programming method to program the RKE system. However, the SKREEM/WCM will only allow RKE programming when the ignition is in the ON position, the PRNDL is in park position, and the VTSS (if equipped) is disarmed.

NOTE: After a SKREEM/WCM is replaced, the ignition/transponder keys need to be programmed to the new SKREEM/WCM. Follow the directions on the diagnostic scan tool. The transponder key for the SKREES/SKIM and the RKE will both be programmed during this operation. There is no need to program the fob of the key for RKE functionality once the transponder key is programmed to the new SKREEM/WCM.

TIRE PRESSURE MONITORING (TPM)

The SKREEM monitors the signals from the tire pressure sensor/transmitters and determines if any tire has gone below the low pressure threshold LOW TIRE PRESSURE THRESHOLDS table.





CRITICAL AND NON-CRITICAL SYSTEM ALERTS

CRITICAL: A critical alert will be triggered when a tire pressure has gone below a set threshold pressure. The SKREEM will send a message to the cluster to display "X TIRE(S) LOW PRESSURE". "X" will be the number of tires reporting low pressure. The message will display for the duration of the current ignition cycle or until an EVIC button is pressed. If the display is removed without correcting the condition, it will reappear 300 seconds to warn the driver of the low pressure condition.

NONCRITICAL: A noncritical alert will be triggered when no signal is received from a sensor/transmitter or when a sensor/transmitter low battery condition is detected. The cluster will display "SERVICE TIRE PRESS. SYSTEM."