Starting Off And Stopping The Vehicle, Function - GF27.10-P-3110KJ

TRANSMISSION 700.4 in MODEL 453.0/3/4 

Function requirements of moving off and stopping the vehicle, general 

• Circuit 15 ON
• Network management over Controller Area Network (CAN) (CAN bus)
• Drive train operational and combustion engine running
• Transmission not in limp-home mode

General 

When moving off the initial state is the vehicle standstill. When stopping the final state is likewise the vehicle standstill.

The dual clutch transmission control unit (N15/13) recognizes or it can use an evaluation of the following input signals to forecast, whether and when the vehicle is at a standstill or is coming to standstill:

• Engine speed, from ME-SFI [ME] control unit (N310)
• Accelerator pedal position, from accelerator pedal sensor (B37) over the ME-SFI [ME] control unit
• Wheel speeds, from left front axle rpm sensor (L6/1), right front axle rpm sensor (L6/2), left rear axle rpm sensor (L6/3), right rear axle rpm sensor (L6/4) over the Electronic Stability Program control unit (N30/4), interior CAN (CAN B), drive train CAN with the ME-SFI [ME] control unit interface
• Service brake operated, from brake lights switch (S9/1) over the dual clutch transmission control unit

Function sequence 

The moving off and stopping the vehicle function is split up into the following function sequences:

• Starting off the vehicle 
• Stopping the vehicle 

Starting off the vehicle 

Moving off takes place in 1st gear. This maximizes fuel economy. In temporary transmission mode "M" the engine rpm is restricted by the rpm limiter in the ME-SFI [ME] control unit.

Stopping the vehicle 

If the vehicle speed drops noticeably, the dual clutch transmission control unit automatically shifts back, to have the ideal gear engaged and ready for any required acceleration. In temporary transmission mode "M" a downshift is made close to the internal combustion engine's idle speed. It is possible to shift down across several gears. If the vehicle comes to a standstill, 1st gear is engaged.

	Electrical function schematic for vehicle start-off and stop function		PE27.19-P-2064-97BBA
	Overview of system components for dual clutch transmission		GF27.10-P-9994KJ