Radiator Cooling Fan: Testing and 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 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.




- 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:
- ECT sensor (characteristic)
(See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [L3].)
- Fan control signal circuit (between fan control module terminal B and PCM terminal 1R)
- If the all items are normal, replace fan control module.