Electric Fan
The electric cooling fan is controlled by the ECM for engine cooling system and air conditioning system requirements. The ECM uses a remote power output final stage (mounted on the fan housing). The electric fan is controlled by a pulse width modulated signal from the ECM.
The fan (and speed) is activated by the ECM based on:
- Coolant outlet temperature
- Catalyst temperature (calculated by the ECM)
- Vehicle speed
- Battery voltage
- Air Conditioning refrigerant pressure (calculated by IHKA and sent via the PT CAN bus to the ECM)