A/C - Changes to Automatic Climate Control (IHKA) Panels
Group 64Heating and Air Conditioning
Bulletin Number
64 75 98
Woodcliff Lake, NJ
January 1998
Product Engineering
SUBJECT: Changes to Automatic Climate Control (IHKA) Panels
MODELS: 7 Series (E38) from 9/96 production
5 Series (E39) from 9/96 production
General Information:
Due to changes made to IHKA control panels on 7 Series (E38) and 5 Series (E39), the older style panels are no longer available. If replacement becomes necessary the new style panel must be retrofitted, and a customer has to be informed about new features of the unit.
Changes to 7 Series (E38) IHKA control panel:
The IHKA control panel has changed in appearance and operation. The blower speed control wheels have been replaced by rocker switches. The push buttons for Front and Rear defrost, AIC control and AUC control are now mounted in a single row at the bottom center of the control panel.
1. -pre 9/96 production
2. -after 9/96 production
The major changes in the operation of the system as of 9/96 are:
A new AUTO-symbol" is used in the LCD display in addition to the illuminated LED on the "AUTO-button".
^ The "AUTO-symbol" in the LCD indicates the automatic fan speed program being activated.
^ The illuminated LED on the "AUTO-button" indicates activation of the automatic air distribution program.
^ When both are displayed, the system is in the fully automatic mode.
If one of the manual distribution buttons is selected, the automatic air distribution is canceled and the "AUTO-button" LED goes out (e.g. on the illustration passenger face vent button was selected).
However, the fan speed remains in the auto mode, with "AUTO-symbol" being displayed on the LCD.
If the fan rocker switch is pressed, when the system is in the AUTO mode, the blower speed is switched to manual control. The "AUTO-symbol" in the LCD display goes out.
However, the air distribution remains in the automatic mode with the LED being illuminated on the "AUTO-button" (1)
Switching off IHKA can still be done by pressing the minus fan rocker switch on the driver side one more time, after reaching the lowest setting. However, the system stays off only for 16 minutes, to prevent windows from fogging. After that time it automatically turns itself on, to the latest previously selected setting.
Changes to 5 Series (E39) IHKA control panel:
The operation and appearance of the IHKA on the E39 as of 9/96 production
has changed only slightly:
On the LCD display the new "AUTO symbol" replaced the fan symbol, indicating activation of the automatic blower speed program.
The lit LED on the "AUTO-button" indicates activation of the automatic air distribution program.
Note:
From 9/96 to 3/97 Production:
When in the automatic blower speed mode, the "AUTO-symbol" and the blower wedge silhouette will be displayed.
After 3/97 Production:
When in the automatic blower speed mode, the "AUTO-symbol" and the actual blower speed indicated by the bars, will be displayed. The number of bars will automatically change as the auto control of the blower takes place.
If the plus or minus fan speed button is pressed when in the auto mode, the "AUTO-symbol" in the display will be turned off and the manual blower speed control takes place. Blower speed is indicated by the bars.
At the same time the automatic air distribution program is still active and the LED in the "AUTO-button" will be:
1. turned off- from 9/96 to 3/97 production
2. turned on- after 3/97 production
If one of the air distribution is pressed when in the auto mode (1), the air distribution will come out of the automatic program, however the automatic blower speed program will remain active and the "AUTO-symbol will continue to be displayed in the LCD panel.