DESCRIPTION
Each radiator fan is made of plastic. It is driven by an electric motor which is retained on a shroud.
Scheme 8
To reduce fan noise, the fan output is two-stepped and can be switched to Low or High according to the load on A/C, coolant temperature, and vehicle speed. This control is accomplished by a circuit as shown below; the output is changed by switching the connection of two motors between serial and parallel instead of using components such as resistors.
Scheme 9
The ECM receives signals from the engine coolant temperature sensor, vehicle speed sensor and A/C switch, and based on these signals, the ECM controls the radiator fan speed to high or low.
Operation example
| Vehicle speed | A/C compressor load | Engine coolant temperature | ||
|---|---|---|---|---|
| Rising: below 94°C (201 °F) Lowering: below 91 °C (196°F) | Rising: between 95 and 96°C (203 and 205°F) Lowering: between 92 and 94°C(198 and 201°F) | Rising: over 97°C (207°F) Lowering: over 95°C (203°F) | ||
| Operation of radiator fans | Operation of radiator fans | Operation of radiator fans | ||
| When accelerating: below 19 km/h (12MPH) When decelerating: below 10 km/h (6MPH) | OFF | OFF | Low-speed | High-Speed |
| Low | Low-Speed | Low-Speed | High-Speed | |
| High | High-Speed | High-Speed | High-Speed | |
| When accelerating: between 20 and 69 km/h (12 and 43 MPH) When decelerating: between 11 and 64 km/h (7 and 40 MPH) | OFF | OFF | Low-Speed | High-Speed |
| Low | High-Speed | High-Speed | High-Speed | |
| High | High-Speed | High-Speed | High-Speed | |
| When accelerating: between 70 and 105 km/h (43 and 65 MPH) When decelerating: between 65 and 100 km/h (40 and 62 MPH) | OFF | OFF | Low-Speed | High-Speed |
| Low | High-Speed | High-Speed | High-Speed | |
| High | High-Speed | High-Speed | High-Speed | |
| When accelerating: over 106 km/h (66 MPH) When decelerating: over 101 km/h (63 MPH) | OFF | OFF | High-Speed | High-Speed |
| Low | High-Speed | High-Speed | High-Speed | |
| High | High-Speed | High-Speed | High-Speed | |
VEHICLE SPEED AND ENGINE COOLANT TEMPERATURE SPECIFICATIONS