Overview
This document contains information on:
General
Function requirements
Function
General
Vehicle standstill is the initial condition when starting off and the final state when the vehicle is stopped.
The dual-clutch transmission control unit or fully integrated transmission control electrohydraulic controller unit detects whether and when the vehicle is at a standstill or is coming to a standstill. This is done by evaluating the following input signals:
Engine speed
Accelerator pedal position
Wheel speeds of all wheels
Service brakes operated
Function requirements
Drive train operational
Engine in operation
Transmission not in limp-home mode
Function
Starting off the vehicle
Irrespective of the selected drive program, moving off takes place in 1st gear. In the Economy or Comfort drive programs, shifting to the next gear takes place at low engine speeds. This makes for an efficient driving style. In the Sport and Sport Plus transmission modes, forced upshifts are made when close to the maximum governed rpm.
Stopping the vehicle
If the vehicle speed is noticeably reduced, the dual-clutch transmission control unit or the fully integrated transmission control electrohydraulic controller unit automatically shifts back to the following drive programs:
Individual (without selection of "Manual shift mode")
Comfort
ECO
The ideal gear is thereby engaged should acceleration be required.
In manual shift mode and in temporary drive program "M", a downshift is made close to the idle speed of the combustion engine. It is possible to shift down across several gears. If the vehicle comes to a standstill, shifting takes place in 1st gear.