Active seat back width adjustment: Introduction

During cornering, lateral forces are exerted on the occupants in the upper body region.

The active seat back width adjustment counters these forces: The backrest side section on the outside moves inwards slightly. This provides the occupants with support in the upper body region. Active seat back width adjustment is available for the driver's seat and the front-passenger seat (option 4MF).

In contrast to the seat back width adjustment which has been familiar until now, the seat back width is now adjusted actively.

2 control units control the active seat back width adjustment:

Active seat back width, driver's seat (ALBFA)
Active seat back width, front-passenger seat (ALBBF)

NOTE: Option 4MF only available in conjunction with option 456, not option 455.
Option 4MF "Active seat back width adjustment" is only supplied together with option 456 "Front comfort seat".
Option 4MF cannot be combined with option "455 Active seat" (installation area for the control unit).

NOTE: Active seat back width adjustment also in M5.
The active seat back width adjustment was developed by BMW M GmbH (component of option 4MA "M Multi-function seats for driver and front passenger").
From 09/2005, the "Sport" map has been changed to M5. Please refer to "system functions".
This change will also be incorporated into the E60/E61 at a later date.

Also new:

From 09/2005, the vehicle electrical system has been modified. The body gateway module (KGM) supersedes the safety and gateway module (SGM).