Theory of Operation
WARNING: This page is about a different car, the 2011 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) sends a CAN bus message to the Totally Integrated Power Module (TIPM) requesting high speed cooling fan operation. The TIPM grounds the coil for the High Speed Cooling Fan Relay through the high speed radiator fan control circuit. The High Speed Cooling Fan Relay then provides battery voltage to the high speed coil in the Cooling Fan Motor.