GF83.75-P-2000SK Residual Engine Heat Utilization System, Function

GF83.75-P-2000SK Residual Engine Heat Utilization System, Function

Function
The residual engine heat utilization allows vehicle heating to continue for up to 30 minutes, even with circuit 15 off and circuit 15C. The system uses the residual engine heat to do this and leads it into the vehicle interior via the blower motor (A32m1). In order to do this the coolant, which is still warm, is passed through the heater heat exchanger by the coolant circulation pump (M13). The heating water circulation pump (M13) ensures that there is an even and bubble-free water flow at the heating system heat exchanger even at low engine speeds.
The coolant circulation pump (M13) is actuated by the HEAT control and operating unit (N18) (without code (580a) automatic air conditioning, without code (581b) comfort automatic air conditioning), the AAC control and operating unit (N22) (with code (580a) automatic air conditioning) or the comfort AAC control and operating unit (N22/7) (with code (581b) comfort automatic air conditioning) via the class B Controller Area Network bus (interior) (CAN-B) to the driver-side SAM control unit with fuse and relay module (N10/1).

The driver side SAM control unit with fuse and relay module (N10/1) reads in this signal and actuates the coolant circulation pump (M13).
If the battery voltage is less than 11.7 volts when the residual engine heat utilization system is switched on via the REST button, the function LED flashes 3 times and the function is switched off again. The function cannot be activated again until the battery voltage has increased to above 11.7 volts.
The blower air temperature control is dependent on the stored outside temperature and the specified temperature that has been selected.
The positions of the actuator motors are saved before circuit 15 off and restored again after circuit 15 on.