Electric Cooling Fan
| ITEM | DESCRIPTION |
|---|---|
| 1 | Electric cooling fan - Main |
| 2 | Electric cooling fan - Auxiliary |
The 2 electric, variable speed cooling fans are installed in a shroud attached to the rear of the radiator. Each electric cooling fan is operated by the engine cooling fan control module, which is integrated into both electric cooling fan motors. The PCM controls the 2 engine cooling fan control modules through a PWM signal. The 2 electrical connectors at the top of the shroud provides the interface between the 2 electric cooling fan control modules and the vehicle wiring harness.
The 2 engine cooling fan control modules are provide with:
- A battery power supply from the EJB.
- An ignition signal from the PCM relay in the EJB.
- A PWM signal from the PCM.
- A ground.
The internal temperature of the electric cooling fan motors are monitored by 2 temperature sensors:
- Sensor 1: This sensor is used to calculate the temperature of active components near the micro controller. The electric cooling fan will stop immediately if the internal temperature reaches 135°C (275°F). At motor stop, after a delay of 120 seconds the diagnostic feedback will be sent. Normal operation will resume when the temperature is less than 120°C (248°F).
- Sensor 2: This sensor is used to measure the temperature of the power stage of the Printed Circuit Board (PCB) to reduce the power if the temperature is too high and to stop the motor in case of an over temperature condition.
The electric cooling fan will derate if the power stage internal temperature reaches 135°C (275°F) and stop motor function at 145°C (293°F). At motor stop, after a delay of 120 seconds the diagnostic feedback will be sent. Normal electric cooling fan operation will resume when the powerstage temperature falls to 135°C (275°F).