BMW 7 Series: Service Information

What Points must be Observed During Servicing

ICM Control Unit

NOTE: If the ICM control unit needs to be replaced, the repair instructions must be observed without fail.

For example, the vehicle battery must be disconnected before removing the control unit and reconnected following the installation. This is the only way to ensure synchronized restarting of the control unit assembly.

NOTE: The ICM control unit must not be exposed to strong vibrations. The integrated sensor system will be destroyed if the housing is struck by hard objects, or if the control unit is dropped. The control unit must not be installed in the vehicle in this case.

NOTE: Only screws and spacer sleeves that are in perfect condition may be used to mount the ICM control unit. Deformed or damaged fixing elements must not be used.

A check must then be carried out to make sure the control unit is mounted securely and free of play.

NOTE: Once the new ICM control unit has been installed, it must be started up with the assistance of the diagnostic system. To do this, the following steps must be carried out (depending on the equipment specification):

• Calibration of the sensors integrated into the ICM
• Calibration of the ride-height sensors
• Initialization of the Integral Active Steering.

Diagnosis in the Event of Signal Faults

NOTE: The ICM control unit itself contains sensors that provide the following signals:

• longitudinal acceleration
• lateral acceleration
• yaw rate.

The wheel-speed signals are recorded and made available by the DSC control unit. The steering wheel angle is determined by the steering angle sensor in the steering column switch cluster.

Instead, the test schedules for the control units that receive these signals only contain references to the transmitter control units which means they do not lead directly to the ultimate cause/solution of the fault.

Sensors in the ICM

NOTE: Calibration of the sensors integrated into the ICM control unit is necessary in the following cases

• the ICM control unit has been replaced or
• if requested by the test schedule in the diagnostic system due to a fault code memory entry.

The calibration must be performed with the vehicle standing on a level surface in the longitudinal and lateral direction. Terminal 15 must also be switched on.

NOTE: The instructions of the diagnostic system must be followed precisely during calibration of the sensors integrated into the ICM. It is particularly important for the vehicle to be standing on a surface that is level in both the longitudinal and lateral directions.

If this is not the case, incorrect correction values will be determined that may cause the dynamic driving system to malfunction.

Ride-height Sensors

NOTE: The ride-height signals in the ICM must be synchronized in the following cases:

• following replacement of the ICM control unit,
• following replacement of a ride-height sensor or
• if prompted to do so by the test schedule of the diagnostic system (due to a fault code memory entry in the ICM).

The synchronization does not have to be carried out if a wheel has been changed.

NOTE: The following points must be observed in order to perform the synchronization using the diagnostic system

• the air suspension control operations must be blocked (remove fuse for EHC control unit)
• the ride-level heights must be measured using a tape measure and
• the rim size must be determined.

The diagnostic system also refers to the ride-level height reference values (design position).

These values are used by the diagnostic system and ICM to calculate the reference values for the conversion that are ultimately saved in the ICM control unit.

The ride-height signals in the EHC control unit (if installed) and the ride-height signals in the ICM control unit must be synchronized together.

Steering Column Switch Cluster with Steering Angle Sensor

NOTE: The steering angle sensor must be calibrated if the steering column switch cluster is replaced or reprogrammed. A calibration must also be performed if this is requested in the test schedule of the diagnostic system as the result of a fault code memory entry.

The steering angle sensor must be calibrated before the ICM can calculate a correct effective steering angle and make this available via the bus system.

NOTE: Once the steering angle sensor has been calibrated, the instructions of the diagnostic system must be precisely followed. The vehicle must be standing on even ground during calibration. The steering wheel must be in the straight-ahead position (visually).

Integral Active Steering

NOTE: The Integral Active Steering must be initialized under the following circumstances

• the ICM, AS or steering column switch cluster control unit has been replaced or
• the steering angle sensor in the steering 1 column switch cluster has been calibrated or
• the steering gear has been replaced or
• if requested by the diagnostic system due to a fault code memory entry in the test schedule.

Displays and Operation

NOTE: New symbols are now used for the yellow DSC indicator and warning lamp and the DTC button. The new DSC symbols used for the first time in the F01/F02 replace the symbols previously used.

READ NEXT: