Procedure And General Test Prerequisites

Information 

• The safety regulations must be observed during all work on the refrigerant system! → 8X00IN Safety regulations for working on air-conditioned vehicles and dealing with refrigerant R134a, → 8X00IN SAFETY REGULATIONS FOR EXTRACTION AND FILLING SYSTEMS .

Information 

• If the specified nominal values are not reached, the air conditioning must be checked for leaks and repaired. 

Information 

• Check condensed water drain tubes: Must not be blocked by wax or underbody protection or otherwise dirty. Condensate must be able to drain away freely. 
• Check fresh-air intake system: Water must not be allowed to run into the air conditioner. Must be completely dirt-free. 
• Check that there is sufficient ventilation in the outside-temperature sensor area. 
• Do not allow heat from the warm engine to build up near the outside-temperature sensor. 
• Check particle filter: Must be dry and not excessively dirty. 
• Condenser must be dirt-free. 
• Make sure that all servo motors/flaps move to their end positions. 
• Switch on MONO mode or SYNC mode using the button on the front air conditioning control panel. 

1. Connect air conditioning service device. → WM 870317 DRAINING AND FILLING REFRIGERANT .
2. Measure outside temperature with a thermometer.
3. Open all air outlet vents on the dashboard, center console and B-pillar (direct the blower near the test person if necessary).
4. Insert sensor of the temperature measuring device approx. 4 cm into the middle of the left center vent. 
5. Check stopwatch and keep an eye on the relevant temperature and high pressure on the air conditioning service unit.
6. Switch on ignition.
7. Hybrid vehicles: Check battery temperature of HV battery. Temperature must be < 35 °C. 
8. Open driver's and passenger's side windows and close sliding roof.
9. Press A/C Max button.
10. Start the engine and leave it running at idle speed (do not rev engine unnecessarily after starting!).

    Hybrid vehicles:  Establish driving readiness (with or without combustion engine running).

11. Operate air conditioner for five minutes at idle speed.
12. Increase engine speed  depending on engine type and maintain a constant engine speed for two minutes  . Start the time measurement immediately.
    1. 12.1. Increase engine speed on V6 petrol vehicles to 2, 000 RPM  .
    2. 12.2. Increase engine speed on V8 petrol vehicles to 1, 900 RPM  .
    3. 12.3. Increase engine speed on diesel vehicles to 1, 500 RPM  .
    4. 12.4. Hybrid vehicles:  Not necessary. Continue with Step 13.
13. Note center vent temperature and pressure values after two minutes.
14. Compare values (center vent temperature and pressure values) with the specified tolerances.