Theory of Operation
WARNING: This page is about a different car, the 2011 RAM Pickup and 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
For the engine to start, the Sentry Key Immobilizer (SKIM) feature of the Wireless Ignition Node (WIN) and the Powertrain Control Module (PCM) must successfully communicate VIN data over the serial data bus. Once the WIN sends the message that a valid Fob-in-Key (FOBIK) is being used, the PCM and WIN perform a "handshake" routine to validate this VIN information, including a positive response from the PCM which allows the engine to run when the ignition state transitions to START. The repair of this fault is determined by the WIN recognition of a valid FOBIK and the ability of the WIN and PCM to complete a successful VIN handshake routine over the bus.