6 Series M6 (S85) Coupe
To start the engine, the gear lever and transmission must both be in "N" (neutral) and the brake must be applied.
When the engine is started, sufficient system pressure must immediately be built up to open the clutch. This is
why the SMG control unit is activated by 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.
Gearshift
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The clutch disengages:
When a gearshift is initiated in manual or automatic mode the SMG control unit actuates the corresponding
solenoid valves. The hydraulic fluid under pressure flows into the clutch slave cylinder. The clutch opens
(disengages).
•
The engine torque is reduced:
Simultaneously, the SMG control unit sends to the DME control unit the message that a gearshift is being
initiated. The engine torque is reduced.
•
Shifting:
The SMG control unit actuates the solenoid valves and the hydraulic shift cylinder. The shift cylinders
execute the forwards and backwards movements of the corresponding shift rods. The desired gear is
selected.
During the gearshift, the engine speed may be raised as required to allow the clutch engagement to be
completed more quickly and more smoothly.
•
Engagement:
When the gear is engaged, the clutch will automatically close.
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, engine speed, road transmission
speed and other controlled variables (e.g. engine oil temperature, selected driving program).
Gearshifts that would result in an excessively high or low engine speed are not executed.
Drivelogic
A total of 11 different driving programs are made available via "Drivelogic".
•
In automatic mode there is a choice of 5 driving programs (from "relaxed" to "sporty").
In driving program 1, for instance, the 2nd gear is selected for pulling away. The clutch operates with great
sensitivity. This eases pulling away on wintry roads.
•
In manual mode there is a choice of 6 driving programs (from "adaptably dynamic" to "very sporty").
Driving program 6 is only available when DSC is deselected or with launch control.
The basic difference in the driving programs lies in their preselected shift times: The higher the driving program,
the engine speed and the load, the shorter the shift time.
Driving in gear lever position "D" (automatic mode)
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Constant-speed travel
Continuous changes of the accelerator pedal position (opening and closing the throttle) are registered in the
SMG control unit. The SMG control unit then suppresses a pendulum shift between adjacent gears (up and
down, e.g. on a motorway journey with constantly changing speed).
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Upshift suppression
Based on the accelerator pedal position, the SMG control unit recognises when the throttle is closed rapidly,
e.g. before applying the brake.
SBT Sequential M transmission E60 M5, E63 M6
BMW AG - TIS
19.01.2013 22:58
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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