5 Series E34 525td (M51) TOUR
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E46 All-wheel drive [system overview ...]
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E46, E53, E83, E85, E86 [system overview ...]
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E60, E61, E63, E64 [system overview ...]
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E65, E66 [system overview ...]
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E70 [system overview ...]
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E87, E90, E91, E92, E93 [system overview ...]
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R56 [system overview ...]
Despite coming from different manufacturers the systems hardly differ from one model series to the next in the way
they appear to the driver (initialisation, RPA indicator and warning light, characteristics, diagnosis).
Important: Responsibility resides with the driver at all times
Check tyre pressures regularly, at least twice a month and before embarking on lengthy journeys.
During initialisation, the set tyre pressure is taken as the initial value for the current set of tyres.
If all 4 tyres loose pressure at the same rate, the wheel speeds will also change at the same rate. The RPA
is unable to detect a uniform drop in pressure in all tyres (e.g. due to diffusion = natural loss of air from all 4
tyres)
Important: Correct function of the Run Flat Indicator is not guaranteed when the emergency wheel is fitted.
As the emergency wheel has a much smaller diameter, the correct operation of the RPA can no longer be
guaranteed.
Brief description of components
The SMG system comprises the following key components:
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4 wheel-speed sensors
The wheel-speed sensors of the Dynamic Stability Control (DSC) measure the wheel speeds of the individual
wheels.
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RPA button
> E46, E53, E83, E85, E86
The RPA button is only needed for initialising the PRA.
(RPA initialisation means "teaching the system the tyre pressures").
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CID: Central Information Display
Vehicles that are equipped with CID are initialised using the CID.
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On-board computer button and rocker switch on turn-signal/main-beam switch
> E87, E90, E91, E92, E93, R56
Initialisation is performed on the LCD display, using the BC button and the rocker switch on the turn-signal/main-
beam switch. The on-board computer functions are selected with the rocker switch.
The R56 does not have a rocker switch. The on-board computer functions are selected with the BC button.
The RPA software is in the following control units, depending on model series:
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RPA control unit
> E46 all-wheel drive
The E46 All-wheel drive has a separate RPA control unit.
The 4 wheel-speed sensors measure the wheel speeds. The DSC control unit sends the signals through
4 direct wires to the RPA control unit.
SBT Run Flat Indicator All models
BMW AG - TIS
23.01.2013 11:53
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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