E38 & E39 IHKA Systems Update

E38 IHKA







The IHKA Control Panel/Module for the 1997 E38 has changed in appearance and operation. The blower speed control wheels have been replaced by rocker switches on the heater control panel. The push buttons for Front windshield defrost, rear window defrost, A/C control and AUC control are now mounted in a single row at the bottom center of the control panel.

The major changes in the operation of the system is in the automatic mode and in the control panel display. In addition to full Automatic operation, the fan speed or the air distribution can also operate separately in an automatic mode. This will depend on the driver's settings on the control panel

When "AUTO" button is pressed, the system is in the fully automatic mode. The auto LED is illuminated and "AUTO" is displayed on the LCD panel along with the blower fan wedge display. If one of the manual distribution buttons is selected, the auto distribution is canceled and the auto LED goes out. However, the fan speed remains in the auto mode, with "AUTO" displayed on the LCD.

If the fan rocker is pressed, in the auto mode, the blower speed is switched to manual control. The auto display indication goes out and the driver can select the desired blower speed. However, the air distribution remains in the automatic mode. Both the driver's and passenger's side control operate with this separate air distribution/blower control.

The interior temperature sensor fan is also an integral part of the control panel. It is not separately replaceable. The 1997 IHKA control panel module can be retrofitted into pre 1997 vehicles as a replacement part.

E39 IHKA







The operation of the E39 IHKA system has changed slightly. It is similar in operation to The E38 except there is no separate passenger control for air distribution or blower tan speed.

For the 97 Model year, the fan symbol in the display has been changed to "AUTO". When the "AUTO" button is pressed, the system is in the fully automatic mode (including blower speed).







UP TO 3-97 PRODUCTION: When in the fully auto program, the blower speed is indicated as an "outline" (actual speed is not indicated.)

If the blower rocker switch is pressed, the "AUTO" display turns off and the blower control is in manual mode (wedge). The balance of the systems function is still in auto mode.

AFTER 3-97 PRODUCTION: When in the fully auto program the blower speed is indicated by the solid wedge as the actual blower speed. The wedge will automatically change as the auto control of the blower takes place.

If the blower rocker switch is pressed, the auto display turns off but the wedge is still displayed.

However in both of these cases, the air distribution will remain in the auto program even though the auto LCD on the button will go out. At this point none of the distribution buttons will be illuminated. If one of the air distribution buttons is pressed in The auto mode, the air distribution will come out of the auto mode. The blower will remain in the auto program and Auto will continue to be displayed in the LCD panel.