OPERATION
A cooling fan control system in which the ECM controls the cooling fan speed is used. Cooling fan speed is controlled in accordance with the engine coolant temperature, hybrid system coolant temperature and the air conditioning operating conditions.
This control is accomplished by operating the 2 fan motors in 2 stages. The fan motors operate in series to achieve low speed, and in parallel to achieve high speed.
| Air Conditioning Operating Condition | Engine Coolant Temperature | Hybrid System Coolant Temperature | Relay Operation | Cooling Fan Motor Connection | Cooling Fan Operation | ||
|---|---|---|---|---|---|---|---|
| No. 1 | No. 2 | No. 3 | |||||
| Off | Low | Low | Off | Off | Off | Off | Off |
| High | Low | On | On | On | Parallel | High | |
| High | High | ||||||
| A/C Pressure "Low" | Low | Low | Off | Off | On | Series | Low |
| High | Low | On | On | On | Parallel | High | |
| High | High | ||||||
| A/C Pressure "High" | High | Low | On | On | On | Parallel | High |
| High | High | ||||||