GENERAL INFORMATION
- The cooling system is designed to keep every part of the engine at appropriate temperature in whatever condition the engine may be operated. The cooling method is of the water-cooled, pressure forced circulation type in which the water pump pressurizes coolant and circulates it throughout the engine. If the coolant temperature exceeds the prescribed temperature, the thermostat opens to circulate the coolant through the radiator as well so that the heat absorbed by the coolant may be radiated into the air. The water pump is of the centrifugal type and is driven by the drive belt from the crankshaft. The radiator is the corrugated fin, down flow type.
- PremAir® direct ozone reduction (DOR) radiator has been adopted to vehicle for California emission regulation. A catalyst which depollutes ozone (O3) in the air has been insufflated to the radiator core.
Scheme 1
CIRCUIT OPERATION
- The cooling fan motor is energized by the fusible link number 28 and fusible link number 29.
- The ETACS-ECU controls the radiator fan relay, fan control relay, and condenser fan relay for driving the cooling fan motor by using the input signal transmitted from the A/C switch, engine coolant temperature sensor, and output shaft speed sensor.
TECHNICAL DESCRIPTION
If the cooling fan does not operate, the following cases may have occurred.
- Malfunction of power supply or ground circuit
- Malfunction of cooling fan motor
- Malfunction of fan control relay, radiator fan relay or condenser fan relay
- Malfunction of ETACS-ECU
- Abnormality of engine coolant temperature sensor input signal transmitted to ECM
- Abnormality of output shaft speed sensor input signal transmitted to TCM
- Abnormality of A/C switch input signal transmitted to A/C-ECU