A/C - Poor Performance At Start Up Or When Idling
SI B64 03 05Heating and Air Conditioning
May 2011
Technical Service
This Service Information bulletin supersedes SI B64 03 05 dated March 2010.
[NEW] designates changes to this revision
SUBJECT
Air Conditioning System Poor Performance
MODEL
E60, E61 (5 Series) with 6 cylinder engines only
SITUATION
The customer may experience one of the following conditions:
1. The air conditioning system has permanent insufficient cooling, especially during idling or while driving in heavy traffic conditions with high outside temperature even when the system is set to "MAX" A/C.
2. No cold air from air conditioning during the first 2 minutes of operation after starting the engine. After this time the system seems to work properly.
CAUSE
1. Compressor failure due to damaged internal control valve.
2. This is considered normal system operation. When the vehicle is parked for extended periods, liquid refrigerant can migrate into the compressor. It may take up to 2 minutes to displace the liquid refrigerant from the compressor before starting normal operation.
PROCEDURE 1
[NEW] Refer to SI B64 04 07. Heating and Air Conditioning Symptom Diagnosis.
PROCEDURE 2
Do not replace any parts. This is considered normal operation of the system. Explain to the customer that this condition may occur if the vehicle is parked for extended periods (greater than 8 hours). Over time liquid refrigerant can drain back into the compressor when the vehicle is parked. If the A/C system were to function at 100% right from startup the compressor would be damaged. The system is then started up gradually to prevent this from happening and extending the life of the compressor. Normally the system is functioning at 100% after 30-60 seconds, but in extreme conditions it may take up to 2 minutes for the system to function at 100%.
[NEW] WARRANTY INFORMATION
This service information bulletin is intended to provide technical diagnostic and/or repair information only.
If a warranty claim results from the above repairs, it should be submitted following the regular warranty claim procedures.