PR25DD engine
System Diagram
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Component parts |
Function |
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Crankshaft position sensor |
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Engine coolant temperature sensor |
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Battery |
ECM receives the battery voltage signal. |
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A/C auto amp. |
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Combination meter |
ECM receives the vehicle speed signal via CAN communication. |
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IPDM E/R |
ECM transmits the A/C relay control signal via CAN communication. |
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Cooling fan relay |
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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].
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: Less than 30% (OFF <- low-speed) |
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: More than 40% (OFF -> low-speed) |
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: Less than 50% (low-speed <- high-speed) |
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: 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.
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Cooling fan speed |
Cooling fan relay |
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1 |
2 |
3 |
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Stop (OFF) |
OFF |
OFF |
OFF |
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Low (LOW) |
ON |
OFF |
OFF |
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Middle (MID) |
OFF |
ON |
OFF |
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High (HI) |
OFF |
ON |
ON |