Electronic accelerator function - GF30.20-P-3015MMC

ENGINES 157.9 in MODEL 216.3, 221.0/1 

ENGINES 278.9 in MODEL 216.3, 221.0/1 

Function requirements for the electronic accelerator, general points 

• Circuit 87M ON (engine control ON)
• Engine running

Electronic accelerator, general points 

The electronic accelerator function (EFP) is integrated in the ME-SFI [ME] control unit (N3/10), and controls the engine torque according to driver requests and operating conditions.

The ME-SFI [ME] control unit regulates the engine torque according to the following sensors and signals:

• Accelerator pedal sensor (B37), accelerator pedal position
• ESP control unit (N47-5), brake actuation via the chassis CAN (CAN E)
• ESP control unit, cruise control request via the chassis CAN
• Video and radar sensor system control unit (N62/2) (for code (233) DISTRONIC PLUS

  for code (237) Active Blind Spot Assist

  for code (238) Active Lane Keeping Assist), DISTRONIC request via the chassis CAN

• Electric controller unit (VGS) (Y3/8), gear range over the engine compartment (CAN C)
• Electric controller unit (VGS), reverse travel signal via drive 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 according to a performance map depending on accelerator pedal sensor signals. To do this the ME-SFI [ME] control unit actuates the actuator motor (M16/6m1) in the throttle valve actuator (M16/6) by means of a pulse width modulated signal (PWM signal), the ignition angle effectiveness over the ignition timing of the ignition coils (T1) and spark plugs (R4) and the boost pressure over the boost pressure regulator (Y77/1). The engine torque is only then defined by the accelerator pedal position if there are no limiting or increasing torque requests active from other functions or control units (e.g. a CC request). 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 in the engine torque as a result of a rapid movement of the accelerator pedal. The limitation serves to improve the ride comfort since any jolting in the drivetrain is prevented. The driveability functions and the throttle change damping take place on the basis of the following sensors and signals:

• Accelerator pedal sensor, accelerator pedal actuation (fast, slow)
• Crankshaft Hall sensor (B70), engine speed
• Coolant temperature sensor (B11/4)
• Pressure sensor downstream of throttle valve actuator (B28/7), intake manifold air pressure
• ESP control unit, vehicle speed via the chassis CAN

Function sequence for reverse travel 

If the electric controller unit (VGS) transmits the CAN signal "reverse travel" via the drive train CAN, the engine torque is limited to about 50% by the ME-SFI [ME] control unit. This optimizes ride comfort and driving safety when reversing.

Function sequence for adaptive accelerator pedal 

The ME-SFI [ME] control unit alters the response time of the accelerator pedal depending on the vehicle speed. A somewhat steeper accelerator pedal curve is used at high vehicle speeds 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 are:

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

	Electrical function schematic for electronic accelerator	Model 216	PE30.20-P-2050-97CAH
		Model 221	PE30.20-P-2050-97SAG
	Overview of system components for gasoline injection and ignition system with direct injection		GF07.70-P-9998MMB