BMW 7 Series: Service Information

Calibration of the Drivers/front-Passenger Seat in the US Version

The position of the driver's seat in the longitudinal direction can become implausible in the course of that seat's life. This can be caused by repeatedly moving the seat forward and back in the longitudinal direction.

These movements can give rise to an unauthorized position delta which no longer provides for a determination of the seat position.

The seat must therefore be recalibrated. Calibration is easy and can be performed by the customer him-/herself.

Fig. 124: Identifying Absolute Seat Position

ABSOLUTE SEAT POSITION CHART

1. Relative seat position
2. Absolute seat position
3. 5% woman area

Blue arrow - Total seat-adjustment travel
Red arrow - Seat-adjustment travel (5% woman)

NOTE: The seat must be moved in the mechanical front stop. Then the seat is calibrated and can be adjusted in the desired seat position.

If the seat is unable to reach the mechanical front stop, the calibration must be performed in the service garage/workshop.

This situation can come about if, for example, a coin is stuck in the seatadjustment rail and blocks the adjustment travel.

If repairs are made to the seat, the seat must always be calibrated. This is necessary to guarantee seat-position recognition, or more precisely to increase the safe and reliable function of seat-position recognition.

Switching the seat control unit for test purposes for example with one from another vehicle is possible. The seat calibration will be lost however. Because the possibility of the calibration being in order when the old seat control unit is reinstalled cannot be ruled out, it is necessary to calibrate the seat.

NOTE: The ACSM receives a message from the seat module once a second as to whether calibration of the seat is necessary.

As soon as the message contains the information "Calibration necessary", the ACSM outputs a Check Control message via the PT-CAN to the instrument cluster.

The seat control unit can likewise trigger the Check Control message. This is possible if for instance the Hall sensor of the longitudinal drive motor is defective. A repair in the garage/workshop will therefore be necessary.

The seat must be calibrated after the repair.

CENTRAL LOCKING BUTTON REFERENCE CHART

Replacing Components

The seats consist of a large number of components. For this reason, the components can be replaced if one becomes faulty.

The Repair Instructions must be observed when replacing or making repairs to a seat. It is also important that only genuine BMW replacement parts are used. This ensures that the seat functions remain intact.

For example, the motors for the seat adjustment cannot be replaced separately from the corresponding output shaft, because they form one electromechanical unit.

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