Airflow Control

WARNING: This page does not describe the selected car, but rather 33 other vehicles, including the 2010 BMW M5, 2009 BMW M5, 2008 BMW M5, 2008 BMW 760Li, and 2007 BMW M5. However, it is still accessible from the selected car via links, so may be relevant.

The airflow control is dependent on the following settings and control actions:

Manual blower setting
The blower setting is made with the rotary switch in the IHKA controls.
Automatic blower and flap setting
The automatic blower and flap functions are activated when the AUTO button is pressed.
Automatic blower speed increase
The automatic blower speed increase function is available with both manual and automatic flap settings.

To make a rapid heating or cooling possible from extreme interior temperatures, the standard range of adjustment is extended.
Dynamic pressure compensation
Without dynamic pressure compensation, the airflow through the fresh air grille would be increased disproportionately with increasing road speed. This effect is compensated for by the opening angle of the fresh-air flap being reduced as speed increases. (The road speed comes from the instrument cluster, through the body CAN to the IHKA control unit. The opening angle is regulated according to an empirically defined map.)
Blower control
If needed, priority levels are transmitted (through the body CAN) from the power module consumer cutoff to reduce the blower output.
Effect of terminal 50
During the starting process (terminal 50 ON), the blower is set to OFF to relieve the vehicle battery.