Function
The residual engine heat utilization feature can be switched on by pressing the residual engine heat utilization button ( ) on the pushbutton control module or in the center console (on taxi version). The system then operates automatically in the following states:
Passenger compartment temperature depending on setting on temperature dials and display
Blower low speed
Defroster nozzles leak air (automatic A/C) (manual on HEAT and Tempmatic A/C)
Footwell open (automatic A/C) (manual on the HEAT and Tempmatic A/C)
Battery voltage > 11.8V
Time limitation 30 minutes or ignition ON