Heater Circuit Function

GF83.20-P-2003RI Heater Circuit Function

General function requirements
^ Circuit 61

Heating circuit, general
Driven by the coolant pump, the coolant circulates in the engine cooling circuit. In the process, it absorbs engine heat. The heated coolant passes through the heater heat exchanger, which dissipates heat to the air blowing by.

The AAC [KLA] control and operating unit (N22) controls the flow of temperature-controlled coolant to the heat exchanger via the heat exchanger shutoff motor (M16/32).
The heater circulation pump (M13) is also actuated at slow engine speeds.
This ensures that the flow volume is adequate for heating the passing flow of air.
The request for switching the heater circulation pump on and off is transmitted by the AAC [KLA] control and operating unit to the front passenger-side SAM control unit (N10/11) via the interior CAN. The front passenger-side SAM control unit switches the heater circulation pump on and off accordingly.