System Description
SYSTEM DESCRIPTION1. FAN CONTROLLER CONTROL DESCRIPTION
The ECM calculates the engine coolant temperature, air conditioning switch, air conditioning refrigerant pressure, engine rpm, and vehicle speed signals. Based on this information from the ECM, the cooling fan ECU controls the cooling fan motor rpm smoothly. This supports cooling and air conditioning performance. The cooling fan ECM controls the Pulse Width Modulation (PWM) to improve gas mileage and save power.