64 50... Air Conditioner Test (R134a)
Before A/C efficiency test, satisfy following conditions:
- Provide a MoDiC or DIS. Safeguard electrical system integrity by checking the fault memory (no faults in the fault memory).
- Provide a thermometer with separate gauge.
- Perform the test in a suitable work bay with an ambient temperature between 20°C and 30°C.
Re 1:
Connect MoDiC or DIS to car and display evaporator temperature.
Re 2:
Position a thermometer with a separate gauge approx. 5 cm below the roof liner at the height of the B-pillar. Lay gauge outwards out of vehicle interior.
Re 3:
Heating up vehicle interior:
- A/C button is not activated during heating up.
- Close all windows and doors.
- Set recirculated air mode.
- On vehicles with CID: In A/C menu (CID) in Air distribution index tab: select 100 % footwell for driver and front passenger and 100 % defrosting for driver (this applies here to driver and front passenger)
- Select air distribution mode for footwell and defrosting.
- Maximum temperature setting.
- Maximum fan stage.
- Start engine
Cool down passenger compartment:
Turn on air conditioning compressor with "A/C button" at a vehicle interior temperature of 45 °C (measured at the head restraint).
On vehicles with MAX-AC button : Activation of MAX-AC (= maximum cooling power)
On vehicles without MAX-AC button:
Set maximum cooling power by means of following steps:
- Setting minimum temperature
- Blower setting maximum
- Stratification maximum cold (4 blue bars)
- Only ventilation open
- Close remaining flaps (air outlet only from center fresh air grille, left and right)
After 5 minutes measure both ventilation temperatures with a thermometer at the same time (fresh air grille center, left and right). The measured temperature must be = 16° C and the difference between right and left may not be greater than 2° C.
Draw off A/C system if this temperature is not reached. See 64 50 009 Drawing Off, Evacuating And Filling A/C System (R134a) . Measure amount of refrigerant drawn off.
If one or both temperature specifications is not reached drain off heating and air conditioning system. Measure amount of refrigerant drawn off.