Electronic Accelerator Function - GF30.20-P-3015MMY

ENGINE 157.9, 278.9 in MODEL 166 

as of Model Year 2016 

ENGINE 157.9, 278.9 in MODEL 292 

Function requirements for the electronic accelerator, general points 

• Circuit 87M (engine management ON)
• Engine runs

Electronic accelerator, general points 

The electronic accelerator function is integrated into the ME-SFI [ME] control unit (N3/10) and controls the opening angle of the throttle valve dependent upon the driver input and the operating conditions.

The ME-SFI [ME] control unit regulates the throttle valve position, dependent on the following signals:

• Accelerator pedal sensor (B37), accelerator pedal position
• Electronic Stability Program control unit (N30/4), brake actuation via chassis CAN 1 (CAN E1)
• Electronic Stability Program control unit, CC request via chassis CAN 1
• Radar sensors control unit (N62/1) (for code 23P (Driving assistance package), engine torque request via chassis FlexRay (Flex E) and chassis gateway control unit (N93/7)
• Fully integrated transmission control unit (Y3/8n4), gear range via drive train CAN (CAN C)
• Fully integrated transmission control unit, reverse travel signal via the drive train CAN

The requirements of the torque coordination function are also taken into account.

Function sequence for electronic accelerator 

The function sequence is described in the following steps:

• Function sequence for engine torque specification 
• Function sequence for driveability functions 
• Function sequence for reverse travel 
• Function sequence for adaptive accelerator pedal 

Function sequence for engine torque specification 

The ME-SFI [ME] control unit controls the engine torque dependent on a characteristic map, dependent on the accelerator pedal sensor. To do this the ME-SFI [ME] control unit actuates the following components:

• Actuator motor (M16/6m1) in the throttle valve actuator (M16/6) by means of a pulse width modulated signal
• Ignition coils (T1) for regulation of the ignition angle efficiency over the ignition timing
• Boost pressure control pressure transducer (Y77/1) for regulation of the boost pressure

The engine torque is then only determined by the accelerator pedal position if no limited or increased torque requests from other functions or control units (e.g. cruise control request) are active. The actual value potentiometers 1 and 2 (M16/6r1, M16/6r2) report the current throttle valve position to the ME-SFI [ME] control unit.

Function sequence for driveability functions 

The driveability functions and throttle change damping have the task of limiting the change of engine torque as a result of a rapid movement of the accelerator pedal. The limitation serves to improve the ride comfort since jolting in the drivetrain is prevented.

The driveability functions and the throttle change damping take place on the basis of the following signals:

• Accelerator pedal sensor, accelerator pedal actuation (fast, slow)
• Crankshaft Hall sensor (B70), engine RPM
• Coolant temperature sensor (B11/4), coolant temperature
• Pressure sensor downstream of throttle valve (B28/7), engine load
• Actual value potentiometer 1 and 2, throttle valve position
• Electronic Stability Program control unit, wheel speed via chassis CAN 1

Function sequence for reverse travel 

If the fully integrated transmission control unit sends the CAN signal "reverse travel" via drive train CAN, the engine torque is limited to approx. 50 % by the ME-SFI [ME] control unit. This optimizes ride comfort and driving safety in reverse travel.

Function sequence for adaptive accelerator pedal 

The ME-SFI [ME] control unit changes the response time of the accelerator pedal depending on the vehicle speed calculated from the wheel speed. At higher vehicle speeds a somewhat steeper accelerator pedal curve is used in order to improve the response time (reduction of the free travel).

Further functions which support the electronic accelerator and which are described in other documents:

• RPM control
• Torque coordination
• Engine limp-home mode

	Electrical function schematic for electronic accelerator		PE30.20-P-2050-97NBB
	Overview of system components for gasoline injection and ignition system with direct injection		GF07.70-P-9998MNG