X Series E70 X5 3.0Sd (M57T2) OFFRD
The signals from the level sensors are filtered to distinguish between changes in load and other disturbances
such as an uneven road surface. For correct use, two signals filtered at different frequencies are computed for
each signal (low-pass filter with fast and slow filtering).
Fast filtering is always employed when regulation is in progress. This prevents the regulated height from
exceeding the specified level. Slow filtering is employed when the vehicle is in motion. This mode of filtering
eliminates oscillations induced by the road surface.
Both sides of the vehicle are regulated independently.
In other words, the comparison of specification to actual value is performed separately for each side (Exception:
testing the minimum height and the control function "Intermeshing".)
With these control functions, the mean values of the left and right-hand sides of the vehicle are taken into
account. The EHC control unit recognises the different operating conditions from the incoming signals and
messages. Depending on operating conditions, appropriately adapted control functions are activated.
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Parking brake (electromechanical parking brake = EMF)
The vehicle is equipped as standard with an electromechanical parking brake (EMF). The parking brake acts as
a hand brake. The parking brake is actuated via the parking brake button in the central console.
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Exclusion of all safety-critical conditions
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Optimum functionality
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Highest availability
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Highest degree of comfort
The parking brake is designed to secure the parked vehicle against rolling away. When the engine is turned off,
the EMF takes over braking: electromechanically via the servo unit.
When the engine is running, braking is control by the Dynamic Stability Control (DSC): hydraulically via the 4
disc brakes.
New from 10/2007:
The vehicle has an automatic-hold function. The automatic-hold function is activated by a button behind the
parking brake switch. The switch is linked to the EMF.
When the function is selected, the vehicle is hydraulically braked from the first application of the brake by the
DSC until it comes to a complete halt. Stepping on the gas pedal releases the disc brakes and the vehicle
continues in motion. The automated braking and release process supports driving in city traffic or in jams, for
example.
The start assistant for starting on uphill slopes is integrated in the DSC (via signal longitudinal acceleration
sensor).
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Tyre pressure control (US version only)
The tyre pressure control (RDC) is a system for monitoring the tyre pressure when driving.
To this end, the tyre pressure and the tyre air temperature are measured at certain intervals on request by the
RDC control device and telemetrically transmitted to the RDC aerial via a high-frequency transmission path.
The RDC aerial relays the signal back to the RDC control device via a sub-bus. The control device evaluates the
received data.
Then the RDC control device forwards the data if necessary to the instrument cluster (KOMBI).
The driver can thus be informed about any correction required to the tyre pressure or about a flat tyre (check-
control message).
The RDC monitors the tyre pressure throughout the journey.
SBT Electrical systems E70, E71
BMW AG - TIS
06.02.2013 01:03
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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