A/C System Control and Regulation Components

A/C System Control And Regulation Components

NOTE:
- Service work on refrigerant circuit.
- After completion of repair carry out the following:
- Check DTC memory
- Initiate basic setting
- Erase DTC memory
- Electrical testing on components marked with a 1).
- All components marked with a 2) will be activated during the output Diagnostic Test Mode (DTM).
- The center defroster vent for the front windshield can be replaced without removing the instrument panel.

Components in engine compartment and rear of vehicle

1 - Sunroof with solar cells
- Not applicable in USA
2 - Service connection
- Low pressure side
- For measuring, discharging and charging
- Cap with seal, always re-install after using service valve
3 - Dust and pollen filter
- Follow filter change intervals
- Different versions (with or without active carbon filter element)
4 - Threaded connection in refrigerant line (with restrictor)
- Only open the threaded connection when the refrigerant has been discharged from the A/C system.
5 - Service connection
- High pressure side
- For measuring, discharging and charging
- Cap with seal, always re-install after using service valve
6 - Sensor for air quality -G238-
7 - Heated Windshield Control Module -J505-
8 - Accumulator
- Only remove when the refrigerant has been discharged from the A/C system
9 - Coolant FC (Fan Control) Control Module -J293- 2)
- The request to switch on the coolant fan is transmitted to the Engine Control Module (ECM) by the A/C control head -E87- via the CAN-bus system.
- Switches the coolant fans gradually to desired output performance.
- Installed in various versions on different locations depending on vehicle equipment.
- Read Measuring Value Block (display group 014)
10 - Condenser
- Only remove when the refrigerant has been discharged from the A/C system
- Refrigerant lines, removing and installing
- Condenser removing and installing
11 - Outside Air Temperature Sensor -G17-
- Removing
- Disconnect harness connector on temperature sensor and unclip from air guide bracket
- Resistance values
- The measuring value of Outside Air Temperature Sensor -G17- is evaluated by the instrument cluster control module and transmitted to A/C control head -E87- via the CAN-bus comfort system.
12 - A/C Compressor Regulator Valve -N280- 1,2)
- Checking activation and function
13 - Compressor
- Compressor from bracket, removing and installing
- Refrigerant lines on compressor, removing and installing
- Compressor, removing and installing
- The compressor construction differs depending on engine (6-cylinder gas engine)
- Different compressor types are installed depending on country variants (e.g. Denso, model designation 7SEU series USA); See Parts department.
- Ribbed belt, removing and installing
- Pulley, replacing
14 - High Pressure Sensor of A/C system -G65-1)
- Function, removing and installing
- The measuring value of the sensor is displayed in function "Read Measuring Value Block" by A/C Control Head -E87-
15 - Air extraction vents
- Sealing flaps on air extraction vent must be able to move freely and close automatically
- In order for the vehicle interior ventilation to function properly, the air ducts that run through the luggage compartment trim must be unobstructed.
- Checking