System Description
System Diagram
| Component parts | Function |
|---|---|
| Crankshaft position sensor | Crankshaft Position Sensor |
| Engine coolant temperature sensor | Engine Coolant Temperature Sensor |
| Battery | ECM receives the battery voltage signal. |
| A/C auto amp. |
|
| Combination meter | ECM receives the vehicle speed signal via CAN communication. |
| IPDM E/R | ECM transmits the A/C relay control signal via CAN communication. |
| Cooling fan relay | Cooling Fan |
| Cooling fan motor |
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
ECM transmits a pulse duty (PWM) signal to IPDM E/R.
IPDM E/R has threshold value to the pulse duty (PWM) signal and operates cooling fan motor with three phases of [HI (high-speed) /LOW (low-speed) /OFF].
| : Less than 30% (OFF ← low-speed) | |
| : More than 40% (OFF → low-speed) | |
| : Less than 50% (low-speed ← high-speed) | |
| : More than 60% (low-speed → high-speed) |
Cooling Fan Relay Operation
The ECM controls cooling fan relays in IPDM E/R 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 |