B1A29 JEEP – PCM Mismatch With SKIM

B1A29 JEEP Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

B1A29 JEEP Possible Causes

Faulty Wireless Control Module (WCM),Faulty Powertrain Control Module (PCM)

B1A29 JEEP Description

For the engine to start, the Sentry Key Immobilizer (SKIM) feature of the Radio Frequency Hub (RF Hub) and the Powertrain Control Module (PCM) must successfully communicate data over the data bus. Once the RF Hub sends the message that a valid Fob-Integrated-Key (FOBIK) is being used, the PCM and RF Hub perform a handshake routine, encrypted with the VIN, to validate this information, and a match allows the engine to run when the ignition state transitions to Start or a remote start occurrence. The repair of this fault is determined by the ability of the RF Hub and PCM to complete a successful handshake routine over the bus. Whenever a valid FOBIK is in the vehicle and the ignition is turned to the ON position or a valid remote start is active, the RF Hub/PCM handshake takes place. The RF Hub validates that the message is sent to, and received by the PCM. When a valid FOBIK is used and the RF Hub receives a mismatching cryptology code from the PCM as part of the routine, the RF Hub will send the command to flash the Security warning lamp and set this Diagnostic Trouble Code (DTC) as active. The engine will not start and the DTC will remain active until the RF Hub and PCM complete a successful handshake.