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Home >> Mazda >> 2006 >> 3 i, 2.0 F, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting [Engine Control System) >> Engine Control System Operation Inspection >> Cooling Fan Control System Inspection

Cooling Fan Control System Inspection

  1. Verify that the battery voltage is more than 12.4 V  .
    • If the battery voltage is less than 12.4 V  , charge the battery or connect the external power supply.
  2. Connect the WDS or equivalent and access ECT PID.
  3. Turn A/C switch to off.
  4. Verify ECT PID is less than 98 °C {209 °F}  .
    • If ECT PID more than 98 °C {209 °F}  , inspect ECT sensor and related wiring harnesses.
  5. Verify that the cooling fan does not operate with ECT PID is less than 98 °C {209 °F}  while the ignition switch is ON.
    • If the cooling fan operates, inspect for following parts and related wiring harnesses:
      • ECT sensor
      • A/C switch
      • A/C refrigerant pressure switch (High/low pressure)
      • A/C refrigerant pressure switch (Medium pressure)
      • VSS
      • A/C magnetic clutch
      • Fan control signal circuit (between fan control module terminal B and PCM terminal 1W)
        • If the all items are normal, replace fan control module.
  6. Verify the cooling fan operates while the A/C switch to ON with the ignition switch at ON position.
    • If the cooling fan does not operate, inspect for following:
      • A/C switch
      • A/C refrigerant pressure switch (High/low pressure)
      • Fan control module power supply circuit
      • Fan control module GND circuit
      • Fan control signal circuit (between fan control module terminal B and PCM terminal 1W)
        • If the all items are normal, replace fan control module.
  7. Verify that the cooling fan operates with following table.
    PCM CONNECTOR TERMINAL VOLTAGE REFERENCE

      PCM terminal 1R voltage
    B+ (off)(1) 0V (ON)(1)
    Cooling fan speed Middle speed High speed
    (1) A/C refrigerant pressure switch (medium pressure) condition
    • If the cooling fan operation is not specified, inspect for following:
      • A/C refrigerant pressure switch (Medium pressure)
        • If the A/C refrigerant pressure switch (Middle pressure) is normal, replace fan control module.
  8. Turn A/C switch to off.
  9. Start the engine and idle it.
  10. Verify that the cooling fan operating speed increases relative to ECT PID increases.
    • If the cooling fan speed does not increase inspect following: