GF83.20-P-2003RC Heater Circuit Function

GF83.20-P-2003RC Heater Circuit Function

Component Identification:

Function requirements, general
^ Circuit 61

Heater circuit in general
The coolant pump pumps cold coolant through the engine. The coolant absorbs the engine's heat and becomes heated. Then some of the heated coolant is routed through the heater heat exchanger, where the heat is delivered to the interior air. The duo valve regulates the coolant flow through the heater heat exchanger separately for the driver and passenger side.

Most of the coolant does not flow through the heater heat exchanger, but rather from the engine to the coolant thermostat. Depending on the water temperature, it routes the water through the radiator or directly through the engine again.
The heater circulation pump is used to support the coolant pump at low engine speeds and for implementation of the residual engine heat utilization (without code (494) USA version). The heater circulation pump is actuated by the driver SAM control unit with fuse and relay module (N10/1) when requested by the automatic heater control and operating unit (N18) (without code (580) Automatic air conditioning and without code (581) Comfort automatic air conditioning), from the AAC [KLA] control and operating unit (N22) (with code (580) Automatic air conditioning) or from the comfort AAC [KLA] control and operating unit (N22/7) (with code (581) Comfort automatic air conditioning).