Charger V8-5.7L (2008)
Alarm System Transponder: Description and Operation
Operation
OPERATION
When the ignition switch is turned to the ON position, the Wireless Ignition Node (WIN) (also known as the Sentry Key Immobilizer Module/SKIM, the
Sentry Key REmote Entry Module/SKREEM or the Wireless Control Module/WCM) communicates through its antenna with the Sentry Key transponder
within the FOB with Integrated Key (FOBIK) using a Low Frequency (LF) Radio Frequency (RF) signal. The WIN then listens for a LF response from
the transponder through the same antenna. The Sentry Key transponder chip is within the range of the WIN transceiver antenna ring when it is inserted
into the ignition switch.
The WIN determines whether a valid FOBIK is present in the ignition switch based upon the response from the transponder. If a valid FOBIK is
detected, that fact is communicated by the WIN to the Powertrain Control Module (PCM) over the Controller Area Network (CAN) data bus, and the
PCM allows the engine to continue running. If the PCM receives an invalid key message, or receives no message from the WIN over the CAN data bus,
the engine will be disabled after about two seconds of operation. The ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab
Compartment Node/CCN) will also respond to the invalid key message on the CAN data bus by flashing the security indicator ON and OFF.
Each Sentry Key FOBIK has a unique transponder identification code permanently programmed into it by the manufacturer. Likewise, the WIN has a
unique Secret Key code programmed into it by the manufacturer. When a Sentry Key FOBIK is programmed into the memory of the WIN, the WIN
stores the transponder identification code from the Sentry Key FOBIK, and the Sentry Key FOBIK learns the Secret Key code from the WIN. Once the
Sentry Key FOBIK learns the Secret Key code of the WIN, it is permanently stored in the memory of the transponder. Therefore, once a FOBIK has
been programmed to a particular vehicle, it cannot be used on any other vehicle. .
The Sentry Key Immobilizer System (SKIS) performs a self-test each time the ignition switch is turned to the ON position, and will store key-related
fault information in the form of a Diagnostic Trouble Code (DTC) in WIN memory if a Sentry Key FOBIK transponder problem is detected. The Sentry
Key FOBIK transponder chip can be diagnosed, and any stored DTC can be retrieved using a diagnostic scan tool. Refer to the appropriate diagnostic
information.
