A/C - IHKA is Inoperative and Fuse 48 is Blown
SI B 64 08 06Heating and Air Conditioning System
May 2006
Technical Service
This Service Information bulletin replaces S.M. B64 201 03 dated July 2003.
SUBJECT
IHKA Inoperative Fuse 48 Blown
MODEL
E53 (X5)
SITUATION
The IHKA (Automatic Heating Air Conditioning System) functions intermittently and the control panel display blanks out. The temperature settings may also change automatically. Eventually the IHKA cannot be operated anymore.
CAUSE
1. Pinched or chafed M-Bus wiring harness
2. Fuse 48 blown, caused by short in wiring harness
PROCEDURE
Check the following areas for problems:
1. Inspect for a pinched wiring harness, especially in the driver's side knee pad area between the instrument panel carrier and the IHKA housing.
2. Inspect the wiring harness for any chafing damage, especially from the sharp edges of the instrument panel in the glove box area.
3. Check for wiring shorts in the area of the water valve assembly.
4. Inspect the wiring at the auxiliary water pump, especially in the area of the frame rails.
5. If fuse 48 keeps blowing, check the wiring between fuse 48 and the IHKA control panel for shorts.
6. If any damage is found in the wiring, repair the wiring and reposition the harness away from the affected area. Edge protectors can be installed to ensure the wiring is not damaged in the future. The edge protector can be ordered in a unit of 1 meter and can be cut into the appropriate length.
7. If wiring has no shorts and Fuse 48 is not blown, check power supply and ground at the IHKA control module. Ensure pins are not loose at IHKA module connection.
PARTS INFORMATION
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.
Disclaimer