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

Engine 256.9 in model 213, 238, 257, 290 

Up To Model Year 2021 

Engine 256.9 in model 222 

Function requirements, general 

• Engine runs

The ME-SFI [ME] control unit (N3/10) detects the engine running via the evaluation of the crankshaft Hall sensor signals (B70). The ME-SFI [ME] control unit directly reads in the signals of the crankshaft Hall sensor.

Electronic accelerator, general points 

The electronic accelerator function is integrated in the ME-SFI [ME] control unit and controls, depending on the driver input and operating conditions, the opening angle of the throttle valve. The ME-SFI [ME] control unit regulates the throttle valve position, dependent on the following signals:

• Engine load

  Pressure and temperature sensor downstream of turbocharger (B28/17)

• Accelerator pedal position

  The powertrain control unit (N127) reads in the accelerator pedal sensor (B37) signals directly, and transmits the accelerator pedal position via the drive CAN (CAN C1) to the ME-SFI [ME] control unit.

• Brake actuation and cruise control requests

  The Electronic Stability Program control unit (N30/4) transmits the signals via the suspension FlexRay (Flex E), the powertrain control unit, and the drive CAN to the ME-SFI [ME] control unit.

• Reversing and drive range signal

  The control unit for the fully integrated transmission control electric controller unit (Y3/8n4) transmits the signals via the drive CAN to the ME-SFI [ME] control unit.

• Engine torque request (with code 239 (DISTRONIC PLUS) or with code 23P (Driving Assistance Package))

  With Code 239 (DISTRONIC PLUS) 

  The Distance Pilot DISTRONIC control unit (A108/1) transmits the engine torque request via the suspension FlexRay, powertrain control unit and drive CAN to the ME-SFI [ME] control unit.

  With Code 23P (Driving assistance package) 

  The Mercedes-Benz Intelligent Drive control unit (N62/4) transmits the engine torque request via the suspension FlexRay, powertrain control unit and drive CAN to the ME-SFI [ME] control unit.

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

The electronic accelerator function is subdivided into the following points:

• Engine torque control 
• Driveability functions and load change damping 
• Reverse travel 
• Adaptive accelerator pedal 

Engine torque control 

The ME-SFI [ME] control unit regulates the engine torque by:

• Adjusting the opening angle of the throttle valve
• Extending or shortening the fuel injection duration
• Advancing or retarding the ignition angle. In this way, very rapid change of the engine torque is possible.

The ME-SFI [ME] control unit actuates the following components for this purpose:

• Throttle valve actuator (M16/6)
  • Throttle valve actuator motor (M16/6m1)
• Ignition system
  • Cylinder 1 ignition coil (T1/1)
  • Cylinder 2 ignition coil (T1/2)
  • Cylinder 3 ignition coil (T1/3)
  • Cylinder 4 ignition coil (T1/4)
  • Cylinder 5 ignition coil (T1/5)
  • Cylinder 6 ignition coil (T1/6)
• Fuel injection system
  • Cylinder 1 fuel injector (Y76/1)
  • Cylinder 2 fuel injector (Y76/2)
  • Cylinder 3 fuel injector (Y76/3)
  • Cylinder 4 fuel injector (Y76/4)
  • Cylinder 5 fuel injector (Y76/5)
  • Cylinder 6 fuel injector (Y76/6)

The engine torque is solely determined by the accelerator pedal input, if no engine torque requests (e. g. cruise control request) are active.

The ME-SFI [ME] control unit detects the throttle valve position via the following components:

• Actual value potentiometer 1 (M16/6r1)
• Actual value potentiometer 2 (M16/6r2),

Driveability functions and load change damping 

Rapid accelerator pedal movements are not immediately translated into an engine torque. The engine torque is adapted to the request in a dampened manner. This avoids jolting in the drivetrain and improves ride comfort.

For this purpose, the throttle flap is only closed to the idle speed range in a delayed manner in the case of a sudden release of the accelerator. In this way, the engine torque reduces slowly and the vehicle does not slow down with jerks.

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

• Accelerator pedal actuation (rapid, slow)
• Engine speed

  Crankshaft Hall sensor

• Coolant temperature

  Coolant temperature sensor (B11/4)

• Throttle valve position

  Actual value potentiometer 1

  Actual value potentiometer 2

• Wheel speed

  The Electronic Stability Program control unit transmits the signals via the suspension FlexRay, the powertrain control unit, and the drive CAN to the ME-SFI [ME] control unit.

Reverse travel 

During reversing, the throttle valve is opened more slowly and engine torque is limited to approx. 50 %. This optimizes ride comfort and driving safety in reverse travel.

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 speeds. At higher vehicle speeds, a slightly steeper accelerator pedal curve is used in order to improve the response time (reduction of free travel).

Further functions which support the electronic accelerator, are:

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

	Electrical function schematic for electronic accelerator	Engine 256.9 in model 213, 238 up to model year 2021	PE30.20-P-2050-97DBA
		Engine 256.9 in model 222	PE30.20-P-2050-97SEM
		Engine 256.9 in model 257, 290 up to model year 2021	PE30.20-P-2050-97XBB
	Overview of system components for gasoline injection and ignition system with direct injection		GF07.70-P-9998MRT