A/C - Blows Warm Air After a Long Drive
SI B 64 09 06Heating and Air Conditioning
August 2006
Technical Service
SUBJECT
Air Conditioning System Blows Warm Air After Long Drive
MODEL
E90, E91 (3 Series)
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 extreme humid conditions. Once the system is turned off for 10 - 15 minutes the system starts to cool properly.
CAUSE
Temperature threshold of evaporator sensor is too low causing evaporator to ice up.
PROCEDURE
On a customer complaint basis only follow the procedure as outlined in the attachment (Repair Procedure).
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.
Repair Procedure
1. Remove lower dash panel under glove box.
2. Replace evaporator temperature sensor.
3. Remove the IHKA control panel.
4. Disconnect the white ELO connector X01198.
5. Remove the connector cover and locate pin 4 (Yellow/Black wire). Note ETM is incorrect-it identifies this wire as black.
6. Remove the wire from pin 4 location.
7. Locally source a 1K-Ohm (1/2-watt or 1-watt) 5% tolerance resistor from a local Electrical Supplier (for example Radio Shack # 271-153).
8. Cut a repair wire (61 13 0 006 663) to a length of approximately 2-1/2 inches and remove about 1/2 inch of insulation from the cut end of wire.
9. Cut a repair wire (61 13 0 006 664) to a length of approximately 2-1/2 inches and remove about 1/2 inch of insulation from the cut end of wire.
10. Solder the cut end of the wire to each end of the resistor as shown in the photo.
11. Install shrink tube over resistor and wires.
12. Insert wire with female pin (61 13 0 006 663) from resistor to pin 4 of connector.
13. Connect wire with male pin (61 13 0 006 664) from resistor into female pin of wire previously removed from connector pin 4.
14. Tape wires using electrical tape.
15. Reinstall connector cover and reconnect to IHKA control panel.
16. Reinstall panel
17. Test operation and clear all faults. Monitor evaporator temp sensor for plausibility.
18. Submit PuMA case with feedback on success of repair with subject of case "E90 Evaporator Ices up".
Disclaimer