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Home >> Mazda >> 2016 >> CX-9 Signature >> Repair and Diagnosis >> Engine Mechanical >> Cooling Fan >> Engine Cooling System >> Fan Control Module Inspection

Fan Control Module Inspection

  1. Connect the M-MDS to the DLC-2.
  2. Start and warm up the engine.
  3. Monitor the engine coolant temperature with the M-MDS.
  4. Using the simulation function, gradually increase the FAN_DUTY value from 0% to 95%. (Refer to ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.5T)] .)
    • Visually verify that the operation speed of the cooling fan conforms to the override drive.
    • To start the cooling fan from the stopped condition, approx. 5 s  . are needed for start-up preparations before starting the cooling fan.
  5. Using the M-MDS, change the operation condition of the A/C while measuring the engine coolant temperature under the following conditions, and verify that the cooling fan operates correctly.
    • Because there is an intake air temperature decrease control setting, the cooling fan may operate when IAT sensor No. 1 detects 60 °C {140 °F}  or more according to conditions other than those mentioned.
    • Because there is an engine protection control setting, the cooling fan may operate when IAT sensor No. 2 detects 70 °C {158 °F}  or more according to conditions other than those mentioned.
    Engine coolant temperature ° C {°F} A/C operation status Cooling fan operation status
    less than 98 Off Off
    less than 98 On On
    more than 100 Off On
  6. If normal operation cannot be verified in Steps  4 and  5, inspect the input signals of the following parts. Replace the cooling fan motor if all the following parts are normal.
    • ECT sensor
    • Refrigerant pressure sensor