Heater Control Valve: Description and Operation

GF83.20-P-3124RI Heat Exchanger Shutoff Motor, Component Description

Component Identification:

Location
The heat exchanger shutoff motor is located in the right rear side of the engine compartment.

Task
The heat exchanger shutoff motor regulates the flow of temperature-controlled coolant to the heat exchanger.

Function
The heat exchanger shutoff motor is actuated by request of the AAC [KLA] control and operating unit (N22) in such a way that an adequate amount of temperature-controlled coolant is always available.

The heat exchanger shutoff motor is opened:
- In a controlled way, if the calculated outlet air temperature at one or both sides is T > 5 °C
- When the defroster function is started by pressing the defroster button
- When the REST function is started by pressing the REST button

The heat exchanger shutoff motor is closed:
- In a controlled way, if the calculated outlet air temperature at both sides is T < 5 °C
- When the OFF button is pressed
- When engine is switched off

The outlet air temperature is calculated using the following factors:
- Outside air temperature
- Interior air temperature
- Temperature setting
- Fresh air/air recirculation flap position