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 recieves a cooling fan speed request signal, IPDM E/R controls the cooling fan ralay 1, 2, 3, 4, and 5.
| Cooling fan speed | Cooling fan relay | ||||
|---|---|---|---|---|---|
| Cooling fan relay 1 | Cooling fan relay 2 | Cooling fan relay 3 | Cooling fan relay 4 | Cooling fan relay 5 | |
| OFF | OFF | OFF | OFF | OFF | OFF |
| LOW | OFF | OFF | OFF | ON | OFF |
| MID | ON | OFF | OFF | OFF | ON |
| HIGH | ON | ON | ON | OFF | ON |