IHKA Control Module - Display Function Failure
Group 64Heating and
Air Conditioning
Bulletin Number
64 02 98
Woodcliff Lake, NJ
April 1998
Product Engineering
SUBJECT:
Failure of IHKA Control Module
Model:
E38, 7 Series produced up to November of 1995
Complaint:
"Malfunction of the IHKA control module display function: meaningless or no display at all. Operation of the automatic air conditioning system is not possible".
Cause:
IHKA circuit board fitted with incorrect resistor R58.
Affected Vehicles:
E38 (740's with M60 engine, 750's with M73 engine) manufactured between 11/94 and 11/95
Correction:
On a customer complaint basis only, the R58 resistor should be removed from the circuit board of the IHKA control module. During that procedure, the special tool kit (P/N 90 88 6 649 010) sent out through the Automatic Tool Shipment Program should be used.
Procedure:
Important:
The components of the IHKA control module are highly sensitive to electrostatic charges. It is essential to place the IHKA control module on an anti-static mat for the duration of the repair! The anti-static mat and wrist sleeve (PIN 88 88 6 900 333) was sent to you under the Automatic Tool Shipment program. Refer to S.I 04 30 87.
Remove the IHKA control module (refer to Repair Instruction 64 11 750).
Place the unit on the anti-static mat. Put on the wrist sleeve and connect it to a good ground as shown.
Also connect the second ground cable to pin number 3 of connector X18341 (black, 3-pin) of the IHKA.
Remove 4 screws from the IHKA.
Disassemble the IHKA control module. To do this, carefully press on the retaining tabs on the top and the bottom and remove the front panel.
Note:
To make the disassembly possible, the label has to be partially peeled off from the front panel.
Position the IHKA control module as shown in the illustration.
Cover the circuit board with the protective sheet from the repair kit. Cut out the resistor R58 (which can be seen through the opening in the protective sheet) using the snippers from the repair kit. Carefully blow away any residues, or remove them with a clean brush (do not use compressed air!).
Reassemble the IHKA control module. Mark the repair date on the seal label (from the repair kit) with the punch pliers and enter your retailer number on the seal with a fine ball point pen. Attach the label onto the IHKA module.
Note:
The seal label certifies that a BMW authorized repair was performed on the IHKA control module. This is important for any subsequent warranty claims.
Reinstall the IHKA control module in the vehicle and conduct a functional test of the automatic air conditioning system.
Warranty Information:
Covered under the terms of the BMW New Car Limited Warranty of 4 years / 50,000 miles.
Defect Code: 64 11 92 12 00
Remove resistor from IHKA control module
Labor Operation: 00 51 353
Labor Allowance: 6 FRU
Note:
Warranty reimbursement is no longer possible for the replacement of IHKA control modules due to complaints which can be resolved by performing the repair described in this bulletin.