Description & Operation
The Sentry Key Remote Entry Module (SKREEM) performs the functions of what used to be the Sentry Key Immobilizer Module (SKIM), the Remote Keyless Entry (RKE) Module, and the Tire Pressure Monitoring (TPM) System (formerly located within the Compass Mini-Trip Computer (CMTC).
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 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.
NON-CRITICAL: A non-critical alert will be triggered when no signal is received from a sensor/transmitter or when a sensor/transmitter low battery condition is detected. The EVIC will display SERVICE TIRE PRESS. SYSTEM. DIAGNOSIS & Testing
For proper diagnosis and Testing of the Sentry Key Remote Entry Module (SKREEM), use a proper scan tool and refer to the proper Body Diagnostic Procedures information.Remote Keyless Entry
The RKE transmitter uses radio frequency signals to communicate with the SKREEM module. The SKREEM is on the PCI bus. When the operator presses a button on the transmitter, it sends a specific request to the SKREEM. In turn the SKREEM sends the appropriate request over the PCI Bus to the:
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 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 the proper 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.
The SKREEM is capable of retaining up to 8 individual access codes (8 transmitters). If the PRNDL is in any position except park, the SKREEM 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 84F (25C). Use the proper scan tool or the Miller Tool 9001 RF Detector to test the RKE transmitter. Use the scan tool or the customer programming method to program the RKE system. However, the SKREEM 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.Sentry Key Immobilizer
The Sentry Key Immobilizer System (SKIS) authenticates an electronically coded Transponder Key placed into the ignition and sends a valid/invalid key message to the Powertrain Control Module (PCM) based upon the results. The VALID/INVALID KEY message communication is performed using a rolling code algorithm via the Programmable Communication Interface (PCI) data bus. A VALID KEY message must be sent to the Powertrain Control Module (PCM) within two seconds of ignition ON to free the engine from immobilization.
The Sentry Key Remote Entry Module (SKREEM) receives an encrypted Radio Frequency (RF) signal from the transponder key. The SKREEM then decrypts the signal and broadcasts the requested remote commands to the appropriate modules in the vehicle over the Programmable Communication Interface (PCI) data bus. A valid transponder key ID must be incorporated into the RF signal in order for the SKREEM to pass the message on to the appropriate modules.
Automatic transponder key synchronization is done by the SKREEM 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) consists of a SKREEM and a transponder key. Each system has a secret key code unique to that system. The secret key is electronically coded in the SKREEM 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.
Removal & Installation
- Open hood, disconnect and isolate the battery negative cable.
- Wait two minutes for the system reserve capacitor to discharge before beginning any system or component service.
- Remove knee blocker airbag.
- Unsnap instrument panel center stack left bezel from instrument panel assembly.
- Reach up behind the left side of the center stack and disconnect the ignition switch and SKREEM electrical connectors.
- From underneath the ignition switch/lock assembly, loosen the lower retaining screw.
- Remove the two mounting nuts from the front of the instrument panel.
- Push the ignition switch/lock assembly inward toward the bulkhead.
- Remove the SKREEM mounting screw on the ignition lock assembly and separate the SKREEM from the ignition lock assembly.
- Position the SKREEM on the ignition lock housing and install the retaining screw.
- Position the ignition switch/lock assembly up in behind the instrument panel and push rearward.
- Install the two mounting nuts to the front of the instrument panel.
- From underneath the ignition switch/lock assembly, tighten the lower retaining screw.
- Reach up behind the left side of the center stack and connect the ignition switch and SKREEM electrical connectors.
- Position the instrument panel center stack left bezel over retaining slots and firmly snap into place.
- Install the knee blocker airbag.
Verify vehicle and system operation.
CAUTIONDO NOT connect the battery negative cable. Failure to do so could result in occupant personal injury or death.