A/C - Loss of Recirculation Control Settings
Group 64Heating and
Air Conditioning
Bulletin Number
64 04 95
Woodcliff Lake, NJ
July 1996
Product Engineering
This Service Information bulletin supersedes S.I. 64 04 95 (4324) dated December 1995 which should be removed and discarded from your S.I. binder.
Asterisks identifies changes made to this revision.
SUBJECT:
Loss of Air Conditioning and Recirculation Control Settings When Vehicle is Turned Off and Then Restarted
MODEL:
5 Series (E34) - vehicles produced after 1/90
Cause:
The Integrated Climate Regulation (IHKR) control module and the blower motor are both connected to the output of the blower relay (K4). When the ignition is turned to the "OFF" position with the blower switch in any position other than "OFF" the "spin down" of the blower motor can cause the motor to act as a generator, producing a slight voltage. In isolated cases this may affect the IHKR control module causing the module to lose its memory of the Air Conditioning and Recirculation control settings.
Correction:
On a customer complaint basis only, the wiring of the blower relay (K4) should be changed to separate the power supplies for the IHKR control module and the blower motor, according to the procedure below.
*Procedure:
1. Pull back the power distribution box lock and remove cover. Remove cover lock by pushing down. The Power Distribution Box is located on the drivers side of the engine compartment in front of the firewall (as shown in the illustration).*
2. Remove the 5 Torx head screws from the power distribution box.(as shown in the illustration)
3. Remove driver side hood catch: remove 2 mounting bolts, unhook hood release cable from the retaining clip, disconnect micro-switch connector.
4. Lift the power distribution box to expose the underside and locate the 10 pin connector for the K4 blower relay (X58).
NOTE:
At this point it is necessary to identify the system on the vehicle (IHKR2 or IHKRF3). They can be identified as follows:
IHKR 2- Will have 2 wires (2.5 GN/BR and 1 GN/BR/GE) in port 6 of connector X58.
IHKRF3- Will have a single wire (2.5 GN/BR) in port 6 of connector X58.
Steps 5 - 8 are written for the IHKRF3 system. If the vehicle is equipped with the IHKR 2 system the 1 GN/BR/GE wire, which connects port 6 of connector X58 to fuse # 27, should be cut approximately 2.5 cm (1 in) from connector X58. Insulate the exposed wire leading out of the connector with Heat Shrink Tubing, strip the insulation back approximately 1 cm (3/8 in) from the wire leading to fuse # 27, and proceed to step 9.
5. Trace the wire from port 6 on the blower relay connector X58 (2.5 GN/BR) to where it enters one of the two splice bundles located under the power distribution box.
6. Carefully cut the tape surrounding the splice bundle (as shown) and separate the splice containing the wire from port 6 on the X58 connector. Be careful not to damage the wires inside the splice bundle.
7. Identify which of the three wires, at the splice location, is the one that leads to fuse # 27.
NOTE
The wire may be easily identified as it is the only 1.0 GN/BR wire entering the splice location (the other two wires are 2.5 GN/BR).
8. Cut the wire from fuse # 27, as close to the splice location as possible, without damaging the splice or the other wires. Strip the insulation back approximately 1 cm (3/8 in) from the end of the wire leading to fuse # 27.
NOTE:
To insure you have the correct wire perform a continuity check between the end of the exposed wire and the terminal for fuse # 27.
9. Locate the wire at port 8 of connector X58 (.5 GR)
10. Cut the wire approximately halfway between where it exits the connector and where it enters the harness. Strip the insulation back approximately 1 cm (2.5 in) from the two ends of the cut wire and twist together with the wire leading to fuse # 27.
11. Solder the three wires together and insulate with heat shrink tubing.
NOTE:
On the IHKRF3 system, insulate the soldered connection removed from the splice bundle with heat shrink tubing, insert it into the bundle, and re-tape the bundle.
12. Re-assemble the power distribution box, mount the hood catch, and adjust the hood catch position.
NOTE:
For instructions on how to adjust hood catch refer to pg. 41-61/3 of the E-34 Repair Manual.
Warranty Information:
Labor costs are reimbursable under the terms of the applicable BMW New Car Limited Warranty:
Defect Code: 64 11 23 42 00
Labor Operation: 00 51 129
Labor Allowance: 8 FRU