64 50... A/C performance test (R 134a)

WARNING: This page is about a different car, the 2013 BMW 550i GT, 2012 BMW 550i GT, 2011 BMW 550i GT, and 2010 BMW 550i GT. However, it is still accessible from the selected car via links, so may be relevant.

Observe the following conditions prior to the A/C performance test

Connect BMW diagnosis system. Check of the fault memory (no faults in the fault memory).
Attach a thermometer with separate display device to the head restraint and route the display device wiring out of the passenger compartment outward.
Perform the test in a suitable workshop area with an ambient temperature above 18° C.
Vehicle temperature should be approximately the same as the ambient temperature in the workshop.
Engine must be at operating temperature.

Heat passenger compartment

"A/C button" is not activated during the heating process
Close all windows and doors.
Set air recirculation function.
Select air distribution mode for footwell and defrosting.
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)
Maximum temperature setting
Maximum blower speed
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 centre fresh air grille, left and right)

After 5 minutes measure both ventilation temperatures with a thermometer at the same time (fresh air grille centre, left and right). The measured temperature must be ≤ 16° C and the difference between right and left may not be greater than 2° C.

If one or both temperature specifications is not reached DRAIN OFF HEATING AND AIR CONDITIONING SYSTEM . Measure amount of refrigerant drawn off.

If drawn-off quantity does not correspond to SPECIFIED FILL QUANTITY : supplement refrigerant and repeat test.

If capacity is correct, continue troubleshooting by pressure measurement.