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Cooling Fan Control System Inspection

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.
Connect the WDS or equivalent and access ECT PID.
Turn A/C switch to off.
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.

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.
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.

Verify that the cooling fan operates with following table.

COOLING FAN SPEED

PCM terminal 1R voltage

B+ (off)⁽¹⁾

OV (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.

Turn A/C switch to off.
Start the engine and idle it.
Verify that the cooling fan operating speed increases relative to ECT PID increases.
- If the cooling fan speed does not increase inspect following:
  - ECT sensor (characteristic)
    (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .)
  - Fan control signal circuit (between fan control module terminal B and PCM terminal 1W)
    - If the all items are normal, replace fan control module.