A/C Blows Warm Air On An Extended Drive
SI B64 09 06Heating and Air Conditioning
May 2009
Technical Service
This Service Information bulletin supersedes SI B64 09 06 dated October 2006.
[NEW] designates changes to this revision
SUBJECT
Air Conditioning System Blows Warm Air After Long Drive
MODEL
E90, E91, E92 (3 Series) vehicles produced up to August 15, 2006
[NEW] E70 (X5) vehicles produced up to February 27, 2009
[NEW] E71 (X6) vehicles produced up to February 27, 2009
SITUATION
The customer states that the air conditioning system works properly, but after driving on a long trip (approximately more than 1 hour), the system starts to blow warm air. This usually happens under extremely humid conditions. Once the system is turned off for 10 15 minutes, the system starts to cool properly.
CAUSE
Hot air leaks between the evaporator and housing wall, past the evaporator sensor, causing the evaporator sensor to read high.
PROCEDURE
Follow the procedure as outlined below:
1. Ensure that the IHKA system is free of faults and correct as necessary. Note: this situation, as outlined in this Service Information, does not set a fault.
2. Remove the evaporator sensor (refer to Repair Instruction REP 64 11 942).
3. Obtain a self-adhesive foam strip (1) from the Parts department.
4. Ensure that the surface of the sensor (2) is clean.
5. Affix the foam strip (1) to the side of the sensor (opposite the electrical connector), as shown to the left between the plastic ribs.
6. Do not cover the sensor tip with the foam strip.
7. To prevent assembly problems, compress the foam strip prior to reinstallation and then install the sensor immediately. The foam strip will expand to its original thickness after installation.
8. Check the system for proper functionality.
PARTS INFORMATION
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.
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