Cooling Fan Control System Inspection

2010 Mazda 5 Sport, 2.3 L, StandardSECTION 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 M-MDS and access ECT PID.
  3. Turn A/C switch to off.
  4. Verify ECT PID is less than 98°C {208°F}  .
    • If ECT PID more than 98°C {208°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 1R)
        • 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 1R)
        • If the all items are normal, replace fan control module.
  7. Verify that the cooling fan operates with following table.
    COOLING FAN OPERATION CHART

      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:
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.