COOLING FAN SYSTEM PROBLEM SYMPTOMS TABLE

Tech Tips

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

Cooling Fan System
Symptom Suspected Area See page
Cooling fan does not operate (main and sub fan) Engine coolant temperature sensor

Click here

Cooling fan circuit

Click here

ECM

Click here

Cooling fan does not operate (main fan) Cooling fan motor (for main fan)

Click here

FAN No. 1 relay

Click here

Cooling fan ECU (for main fan)

Click here

Cooling fan circuit

Click here

Cooling fan does not operate (sub fan) Cooling fan motor (for sub fan)

Click here

FAN No. 2 relay

Click here

Cooling fan ECU (for sub fan)

Click here

Cooling fan circuit

Click here

Cooling fan does not stop (continues to operate) (main Cooling fan circuit (open in SI and SI2 circuit)

Click here

ECM

Click here

Cooling fan does not stop (continues to operate) (main Cooling fan circuit (open in SI circuit)

Click here

Cooling fan ECU (for main fan)

Click here

Cooling fan does not stop (continues to operate) (sub Cooling fan circuit (open in SI2 circuit)

Click here

Cooling fan ECU (for sub fan)

Click here

Cooling fan speed does not change Cooling fan circuit

Click here

ECM

Click here