Heater circuit function

P83.40-2396-76

1 Coolant compensation tank

2 Coolant pump

3 Engine housing

4 Heating system heat exchanger

M13 Coolant circulation pump

M16/32 Heat exchanger shutoff motor

A Coolant return flow

B Coolant feed

C Vent line

M Motor

Function

The coolant pump pumps cold coolant through the engine. The coolant absorbs the engine's heat and becomes heated. The heated coolant is subsequently guided through the heat exchanger, where the heat is emitted into the air in the interior.

The heater heat exchanger only has a specific volume of coolant flowing through it, sufficient to fulfill the heating requirement.

The AAC [KLA] control and operating unit (N22) (in vehicles without code (581) Comfort automatic air conditioning) or the comfort AAC [KLA] control and operating unit (N22/7) (in vehicles with code (581) Comfort automatic air conditioning) controls the flow of temperature-controlled coolant to the heater heat exchanger via the heat exchanger shutoff motor.

The coolant is routed via the coolant return, in which the coolant circulation pump is located, back to the coolant pump.