Residual Engine Heat Utilization System, Function

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

Function
The residual engine heat utilization permits to heat the vehicle also when the ignition is switched . To do so the system utilizes the OFF residual heat from the engine and guides it via the blower into the passenger compartment.

When the REST button ( REST ) is pressed on the AAC pushbutton control unit (N22) the following program sequence is given:
^ Blend air flaps controlled
^ Coolant circulation pump ON
^ Blower automatically supplied with a control voltage of 35 %
^ Flash fog logic
^ Footwell flaps 100 % OPEN
^ Defroster vent flaps 50 % OPEN
^ Side vent flaps 50 % OPEN
^ Heat exchanger shut-off motor 100 % ON
^ Center vent flap closed
^ Fresh air/recirculated air flap (recirculated air)

End of program
^ By pressing the REST button again ( REST )
^ Time-out of 30 minutes period (repeated operation possible)
^ At a battery voltage of less than 11 V the LED flashes
^ Ignition ON

Residual engine heat can only be utilized when the ignition is switched OFF.
During the residual engine heat utilization function no function buttons are accepted with the exception of the REST button ( REST ) and the set value positioners.

Flash fog logic:
The heated air is routed into the footwell for 60 s only in order to help prevent the front windows from fogging up.