SFI SYSTEM


  1. OPERATION


    1. A cooling fan control system in which the ECM controls the cooling fan speed is used. Cooling fan speed is controlled in accordance with the engine coolant temperature, hybrid system coolant temperature and the air conditioning operating conditions.

    2. This control is accomplished by operating the 2 fan motors in 2 stages. The fan motors operate in series to achieve low speed, and in parallel to achieve high speed.

      A01KE7LE02
      Air Conditioning Operating Condition Engine Coolant Temperature Hybrid System Coolant Temperature Relay Operation Cooling Fan Motor Connection Cooling Fan Operation
      No. 1 No. 2 No. 3
      Off Low Low Off Off Off Off Off
      High Low On On On Parallel High
      High High
      A/C Pressure "Low" Low Low Off Off On Series Low
      High Low On On On Parallel High
      High High
      A/C Pressure "High" High Low On On On Parallel High
      High High

    3. If coolant temperature is extremely high and ambient temperature is high when the power switch is turned off, the ECM operates the engine water pump assembly and cooling fan motors for maximum 3 minutes to ensure engine restartability.