Function
The temperature set on the temperature dials (automatic heater and Tempmatic A/C) or temperature buttons (automatic air conditioning) is achieved or held constant by:
heating the air in the heater core
cooling the air in the evaporator
cooling and reheating (reheat mode)
Heating
The heater core heats the air flowing through which then passes through the air ducts into the vehicle passenger compartment.
The heat given up by the heater core is controlled by the dual valves which control the flow rate of the heated coolant.
The pushbutton control module controls the dual valves.
Cooling (automatic heater)
Cooling is accomplished by closing the dual valves preventing heated coolant from flowing through the heater core.
Cooling (Tempmatic A/C and automatic A/C)
The expansion valve located on the evaporator causes the liquid refrigerant under high pressure to expand reducing the pressure and allowing the refrigerant to evaporate. The heat of evaporation required for this purpose is absorbed from the air flowing through the evaporator. The cooled air then flows through the air ducts into the vehicle passenger compartment.
Reheat mode (Tempmatic A/C and automatic A/C)
After cooling and drying in the evaporator, the air is heated up again in the heater core (reheated). This prevents the windows from fogging up on the inside.
Temperature dial, location/purpose/function | |||
Warm temperature button, location/purpose/function | with code 581a only | ||
Cold temperature button, location/purpose/function | with code 581a only | ||
Dual valve, location/purpose/design/function | |||
Heater core, location/purpose/function | |||
Coolant circulation pump, location/purpose/function | |||
Evaporator, location/purpose/function | with code 580, 581a | ||
Expansion valve, location/purpose/design/function | with code 580, 581a | ||
A/C compressor, location/purpose/design/function | with code 580, 581a up to 31.08.95 | ||
with code 580, 581a as of 01.09.95 | |||
In-car temperature sensor with aspirator blower, location/purpose/function | |||
Heater core temperature sensor, location/purpose/function | up to 31.08.95 | ||
as of 01.09.95 | |||
Evaporator temperature sensor, location/purpose/function | with code 580, 581a | ||
Outdoor air temperature sensor, location/purpose/function | with code 580, 581a |
Referenced documents
- gf8320p2107a Duovalve, location/purpose/function
- gf8320p2108e Heater core, location/purpose/function
- gf8320p2109a Coolant circulation pump, location/purpose/function
- gf8325p2105a Temperature selector, location/purpose/function
- gf8340p2123a Expansion valve, location/purpose/design/function
- gf8340p2160a Warm temperature pushbutton, location/purpose/function
- gf8340p2161a Cold temperature pushbutton, location/purpose/function
- gf8340p2164a Evaporator, location/purpose/function
- gf8355p2100a A/C compressor, location/purpose/design/function
- gf8355p2100e A/C compressor, location/purpose/design/function
- gf8357p2107a In-car temperature sensor with fresh air blower, location/purpose/function
- gf8357p2108a Heater core temperature sensor, location/purpose/function
- gf8357p2108e Heater core temperature sensor, location/purpose/function
- gf8357p2109a Evaporator temperature sensor, location/purpose/function
- gf8357p2110a Outside air temperature sensor position/task/function