Standard Starting System

WARNING: This page is about a different car, the 2018 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

When you press the Keyless Go button (KIN Button), a request is sent to RFH via the private LIN. Once the RFH receives the request from the KIN, it looks for the valid key via the Passive Entry Module (PEM) antennas. If the RFH detects a valid key and if the brake is engaged, then the RFH sets the ignition position to START/CRANK. The BCM then turns the Ignition status to START/CRANK. The BCM then sends command to turn the vehicle to the CRANK. For an vehicle with an IGNM (Ignition Node Module), when the customer turns the key to Start position the RFH sets the ignition to START/CRANK. The brake pedal status is not required to start the vehicle but can be started with brake pedal engaged. The BCM turns the Ignition status to START/CRANK, and sends a command to START the vehicle. The functionality is the same but is a hard wired input. If conditions are correct to start the ECM turn on the high side of the ECM starter relay and turns the Crank Hold Signal to True. As long as the BCM is still in crank, the Crank Hold is true, the BCM turns on the low side of the starter relay and the engine will crank. Once the engine started the ECM deactivates the double start over ride. The BCM will then deactivate the starter when the engine starts or the maximum time has been reach for tip start (10 sec for Gas and 25 sec for diesel). The RFH will change the ignition to the RUN position if, the start type is a tip start, the 5 second time expires or the engine controller indicates that the vehicle is not in park or neutral. The engine can be manually shut down by the driver with speeds over 5 MPH in any gear.