5 Series E60 530d (M57TU) SAL
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Starter inhibitor
The Car Access System (CAS) enables the starter only if a release signal is received from the SMG control unit.
The following conditions must be satisfied for the start to be enabled:
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The gear lever must be in position "N".
The LC display in the instrument cluster must show "N", indicating that the transmission is also in "N".
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The SMG control unit enables the start, the clutch is opened.
System functions
The SMG comprises the following functions:
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Engine start
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Gearshift
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Driving in gear lever position "D" (automatic mode)
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Launch control (acceleration assist system)
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Rock free, e.g. from snow
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Vehicle standstill
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Gear lever position neutral and ignition off
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Emergency program
Engine start
To start the engine, the gear lever and transmission must both be in "N" (neutral).
When the engine is started, sufficient system pressure must immediately be built up to open the clutch. For this
reason, the SMG control unit is activated by a wake-up signal from the car access system (CAS) when the
vehicle is unlocked. The SMG control unit measures the system pressure via the hydraulic pressure sensor. If
the system pressure is too low, the hydraulic pump will be actuated. The hydraulic pump will build up pressure.
When the system pressure has been reached, the SMG control unit will switch the hydraulic pump off again.
With the "prompt signal", the gear lever position indicator in the centre console is activated. If terminal 15 (wake-
up wire) has not been activated approx. 15 minutes after the vehicle was unlocked, the gear lever position
display will be switched off again.
Gearshift
If a gearshift is initiated in manual or automatic mode, the SMG control unit will actuate the corresponding
solenoid valves in the valve block.
The pressurised hydraulic fluid flows into the clutch actuator and opens/closes the clutch.
At the same time, the SMG control unit sends information to the DME control unit that a gearshift has been
initiated and that engine torque must be reduced.
In the next step, the gearshift and selector angle actuator is actuated. At the same time, the gearshift and
selector angle actuator executes the forward/backward movement of the selector shaft, and if necessary turns
the selector shaft.
During the gearshift, the engine speed may be raised as required to allow the clutch engagement to be
completed more quickly and more smoothly.
When the gear is engaged, the clutch will automatically close.
The SMG control unit receives the precise clutch position from the clutch travel sensor.
After the gear change, the solenoid valves are actuated without the use of current.
The course of the entire gearshift depends on the accelerator pedal position, road speed, engine speed and
other factors (e.g. engine oil temperature).
SBT Sequential manual gearbox E60, E61, E63, E64
BMW AG - TIS
22.02.2013 10:11
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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