Component Description For The Fan Motor - GF20.20-P-1000KJE
ENGINE 780 in MODEL 453.091/391/491
Location
The electric vehicle drive motor fan (M46) is located in the vehicle at the rear left directly above the electric drive.
Task
The electric vehicle drive motor is not integrated into the coolant circuit but is cooled over the electric vehicle drive motor fan.
Function
The EDCU (N127) actuates the electric vehicle drive motor fan. In this case, the target fan speed is specified via a pulse width modulated signal by the electric drive control unit.
The duty cycle of the pulse width modulated signal is 10 to 90 %.
This means e.g.:
- 10% fan motor "OFF"
- 20% fan motor "ON", minimum rotational speed
- 90% fan motor "ON", maximum rotational speed
A fault in the fan motor is transferred to the electric drive control unit through a pulse width modulated signal that is periodically (identical interval and identical length) switched to ground.
For faulty actuation the fan motor rotates at its maximum rotational speed (fan emergency mode).
Delayed fan switch off
The fan motor runs on for up to 5 min with "ignition OFF".
The duty cycle of the pulse width modulated signal for delayed fan switch off is a maximum of 40 %. If the battery voltage drops down a lot, the delayed fan switch off is suppressed.
| Wiring diagram for high-voltage battery/power electronics cooling circuit | PE20.00-P-2001-97BEA |