System Description
ECM controls cooling fan speed corresponding to vehicle speed, engine coolant temperature, refrigerant pressure, air conditioner ON signal. Then control system has 3-step control [HIGH/LOW/OFF].
Cooling Fan Operation
Cooling Fan Relay Operation
When IPDM E/R receives a cooling fan speed request signal, IPDM E/R controls the cooling fan relay 1, 2 and 3.
| Cooling fan speed | Cooling fan relay | ||
|---|---|---|---|
| Cooling fan relay 1 | Cooling fan relay 2 | Cooling fan relay 3 | |
| OFF | OFF | OFF | OFF |
| LOW | ON | OFF | OFF |
| HIGH | ON | ON | ON |