A/C - Reduced Air Output or White Mist
Group 64Heating and
Air Conditioning
Bulletin Number
64 01 96
Woodcliff Lake, NJ
May 1996
Product Engineering
SUBJECT:
A/C Evaporator ices up.
MODEL:
E36 with IHKR control unit produced prior to week 24/94.
Complaint:
Reduced air output or white mist emitting from ventilation grilles after use of air conditioning system for any considerable length of time.
Cause:
When the evaporator reaches a temperature of approximately 2° C the IHKR control unit will disengage the clutch on the air conditioning compressor. Normally this would prevent the formation of ice on the evaporator; however, under certain operation conditions the evaporator may ice up resulting in the above complaint.
Correction:
In the vent of a customer complaint, first troubleshoot the system by inspecting the microfilter for contamination and verify that the system is properly charged. If all mechanical components are in proper working order, install the evaporator adapter (BMW part # 61 11 4 392 237) at the two pin connector in the harness leading to the evaporator temperature sensor following the procedure outlined below. The adapter effectively raises the temperature at which the control unit will disengage the compressor clutch to 5°C, thus preventing the formation of ice on the evaporator.
IMPORTANT:
Identification of the IHKR control module production date using DIS software is only possible with CD 7.0 or later.
Procedure:
1 - Identify the production date of the IHKR control unit by connecting the vehicle to the DIS tester, selecting the IHK system, and proceeding to the control unit identification screen. The production date will be displayed in a Week/Year format. If the production date is prior to week 24/94 install the adapter.
NOTE:
Do not install the adapter if the control module production date is week 24/94 or later as the resistor has already been integrated into the control unit.
2 - Remove the three mounting screws for the dashboard lower left trim panel, as shown, and remove the trim panel.
3 - The evaporator temperature sensor is located above the driver's foot well and may be viewed from the shown location.
4 - Identify the evaporator temperature sensor (1) and the two pin connector (2) in the harness leading from the sensor.
5 - Disconnect the two pin connector and install the adapter (1) between the connector ends. Secure excess wire with a wire tie (2).
6 - Affix the warning sticker, enclosed with the adapter, in a visible location on the IHKR control unit (located behind the center console storage compartment).
NOTE:
If the IHKR control unit is replaced at a later date (with a unit produced week 24/94 or later) it is essential that the adapter be removed or the cooling performance of the system will be greatly impaired. The sticker will identify the modification to the system for reference in future repairs.
Warranty Information:
Parts and labor are reimbursable under the terms of the BMW New Car Limited Warranty of 4 yrs./50,000 miles.
Defect Code: 64 51 90 02 00
Labor Operation: 00 51 152 Checking the production date of
Labor Allowance: 3 FRU the control unit.
Labor Operation: 00 51 153 Checking the production date of
5 FRU the control unit, installing the
evaporator adapter, and affixing
the label.
Only one of the above job numbers may be claimed.