BMW 7 Series: A/C Performance Test (R 134a)
Observe the following conditions prior to the A/C performance test
1. Provision of a diagnosis system. Safeguard electrical system integrity by
checking the fault memory (no
faults in the fault memory).
2. Provide a thermometer with separate gauge.
3. Perform the test in a suitable workshop area with an ambient temperature
between 20ºC and 30ºC.
Re 1:
Connect diagnosis system to vehicle 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 passenger compartment.
Re 3:
Heat passenger compartment:
- "A/C button" is not activated during the heating process
- Close all windows and doors.
- Set air recirculation function.
- 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)
- Maximum temperature setting (28ºC)
- Maximum blower speed (adjust 9 pixels from 9 possible on front A/C
control panel)
- Run engine at approx. 2000 RPM until operating temperature is reached,
then idle speed.
Air-conditioning performance test
Turn on A/C compressor via "A/C button" at a vehicle interior temperature of
50ºC.
Vehicles with MAX-AC button ("MAX"):
- Activation of MAX-AC (= maximum cooling power)
Vehicles without MAX-AC button ("MAX"):
- Set maximum cooling power by means of following steps:
- Temperature setting = 16ºC
- Blower setting 9 pixels of 9 possible
- Stratification maximum cold (4 blue bars)
Evaporator sensor temperature must be < or = 15ºC after 3-4; minutes at
approx. 2000 RPM.
DRAW OFF A/C SYSTEM if this temperature is not reached. Measure amount of
refrigerant drawn off.
If drawn-off quantity does not correspond to specified fill quantity, supplement
refrigerant and repeat test. See
AIR CONDITIONING SYSTEM, AMOUNT OF REFRIGERANT.
If capacity is correct, continue troubleshooting by pressure measurement.
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WARNING: Only persons in possession of a professional certificate
of competence for the maintenance and repair of heating and air conditioning
systems are authorized to carry out repair work on the
Work on the refrigerant circuit may only be carried out by experts!
Avoid all contact with liquid or gaseous R 134a. Wear safety goggles and
gloves when working on the
refrigerant circuit.
Follow S
NOTE: Leak detection with forming gas replaces the leak detection that is
prohibited in
EU countries using UV.
Observe national regulations in all other countries!
IMPORTANT: Compliance with the man
SEE MORE:
Notes
WARNING: Risk of injury!
Refrigerant circuit is under high pressure!
Follow safety instructions for handling R 134A refrigerant.
Avoid contact with refrigerant and refrigerant oil.
Follow safety instructions for handling REFRIGERANT OIL.
IMPORTANT: Observe SAFETY INSTRUCTIONS for raising the v
NOTE: Carry out preliminary work as described in REPLACING DRIVE BELT.
Slacken screws (1)
Relieve tension on DRIVE BELT and remove from belt pulley (2).
Unscrew bolts (1) and remove belt pulley (2).
Installation note:
Lettering on belt pulley (2) must point forwards.
Replace microencapsulated scr