System Description
SYSTEM DIAGRAM
SYSTEM DESCRIPTION
ECM controls cooling fan speed corresponding to vehicle speed, engine coolant temperature, refrigerant pressure, air conditioner ON signal. Then control system has 4-step control [HIGH/MIDDLE/LOW/OFF].
Cooling Fan Operation
Cooling Fan Relay Operation
The ECM controls cooling fan relays through CAN communication line.
| Cooling fan speed | Cooling fan relay | ||
|---|---|---|---|
| 1 | 2 | 3 | |
| Stop (OFF) | OFF | OFF | OFF |
| Low (LOW) | ON | OFF | OFF |
| Middle (MID) | OFF | ON | OFF |
| High (HI) | OFF | ON | ON |