Theory Of Operation

WARNING: This page is about a different car, the 2021 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.

The RF Hub Module uses a transponder mode to query the Frequency Operated Button with Integrated Key (FOBIK) for low battery state in keyed ignition systems. This is done after the FOBIK authentication is complete so that it does not impact the starting system timing. The Low Battery condition determination is the responsibility of the FOBIK. The RF Hub receives FOBIK Battery Low information by two methods: 1) If any FOBIK has a low battery condition during authentication for the Keyless-Go feature. 2) If any FOBIK reports a low battery condition within its Remote Keyless Entry (RKE) command to the RFHUB.

The RF Hub also monitors the rolling code synchronization with the RKE transceiver FOBIK. When the FOBIK is pressed over 1024 times, it loses synchronization with the rolling code. Re-syncing automatically takes place in the background after the vehicle has been started and driven above 5 mph. This happens once per ignition cycle above 5 mph to all FOBIKs located inside the vehicle, just in case one of the FOBIKs was de-activated during a FOBIK safe lock procedure.