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.
READ NEXT:
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:
Vehicle features and
options
This chapter describes all standard, country-specific
and optional features offered with the series.
It also describes features and functions that are
not necessarily available in your vehicle, e.g., due
to the selected options or country versions. This
also applies to
Safety information
Warning
The system is designed to operate in certain
conditions and circumstances. Due to conditions
or other factors, the system may not respond.
There may be a risk of accident or risk
of damage to property. Actively intervene as
warranted. Refer to the information in this Own