Automatic air conditioning (auto A/C), function - GF83.40-P-0001S: Notes
MODEL 140 as of 1.9.95 except CODE (498) Japanese version
Function
The automatic air conditioning (auto A/C) consists of an electronically and pneumatically controlled refrigeration, heating and ventilation system which can be summarized with the subfunctions listed below.
- Ventilation
The ventilation provides for the air flow through the passenger compartment. The air flow is supported by the automatic A/C blower or the rear A/C blower in normal operation when the vehicle is standing still or to increase the quantity of air.
The air is distributed in the vehicle passenger compartment by the air distribution flaps.
In order to prevent the windows from fogging up, the footwell flaps are opened completely for 30 seconds after switching on the ignition.
- Automatic air conditioning pushbutton control module
The automatic air conditioning can be controlled by the driver by pressing various function buttons. Moreover, the pushbutton control module receives various sensor signals which it processes and controls components in the automatic air conditioning system.
- Automatic air conditioning temperature control
The desired temperature is achieved and held constant by cooling or heating the air. Precise temperature control is achieved by reading in the values from various temperature sensors.
- Rear air conditioning pushbutton control module
The rear air conditioning can be controlled by the rear passengers with the various function buttons. In addition the pushbutton control module reads in the signals from various sensors directly, processes the signals and controls the components in the rear air conditioning system.
- Heater circuit
The coolant is heated by the engine. Then the heated coolant flows through the heater core (on vehicles with rear air conditioning "code 582" also through the rear heater core), where the heat is transferred to the passenger compartment air. The coolant returns to the coolant pump through the heater return line.
- Refrigerant circuit
The A/C compressor compresses the gaseous refrigerant, which heats up and flows into the condenser where it is cooled. After purification in the receiver/drier the liquid refrigerant is sprayed into the evaporator (on vehicles with rear air conditioning into the rear AC evaporator). The refrigerant evaporates and cools down. The A/C compressor sucks in the refrigerant which has again become gaseous due to the heat absorbed.
- Residual engine heat utilization system
The residual engine heat utilization system makes it possible to heat the vehicle even with the ignition OFF. The system uses the residual engine heat for this purpose and transfers it into the vehicle passenger compartment with the blower.
| Vacuum connections to valve strip changed | up to 04/93 (up to veh. ident no. 123445) | BT83.10-P-0001-01S | |
| Flexible shafts for actuation of center and side nozzles changed | as of 04/93 | BT83.10-P-0001-03S | |
| Main air flap vacuum element replaced by new version | as of 01/94 | BT83.10-P-0001-04S | |
| Auxiliary heater control module replaced by new version | as of 09/95 | BT83.40-P-0001-01S | |
| Automatic air conditioning pushbutton control module replaced by new version | as of 09/95 | BT83.40-P-0001-02S | |
| Emission sensor replaced by new version | as of 09/95 | BT83.40-P-0001-03S | |
| Fluid control in receiver/drier changed | as of 09/95 | BT83.40-P-0001-05S | |
| Refrigerant injection nozzle replaced by new version | as of veh. ident no. 128374 | BT83.50-P-0001-01S | |
| A/C compressor replaced by new version | Engines 104, 119 Engine 603.971 from 09/95 to 05/96 Engine 606.961 as of 06/96 |
BT83.55-P-0001-01S | |
| Engine 120 | BT83.55-P-0001-01B | ||
| Sun sensor replaced by new version | as of 09/95 | BT83.57-P-0001-03S | |
| Ventilation, function | GF83.10-P-2000B | ||
| Vacuum system, function | GF83.10-P-2001B | ||
| Heating circuit, function | GF83.20-P-2003B | ||
| Automatic air conditioning pushbutton control module, function | GF83.40-P-2000S | ||
| Refrigerant circuit, function | GF83.40-P-2001B | ||
| Rear air conditioning pushbutton control module replaced by new version | With code 582 (rear air conditioning) | GF83.50-P-2000S | |
| Temperature control, function | GF83.57-P-2000B | ||
| Residual engine heat utilization, function | GF83.75-P-2000A |