Injection Regulation, Function - GF07.10-P-1004MRD

Engine 274.9 in model 213, 238 

up to model year 2021 

Function requirements, general 

• Engine running.

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

Injection control 

The injection control distributes the required fuel quantity to each cylinder in a demand-based way. The fuel quantity results from the injection duration and the injection pressure when doing this. The ME-SFI [ME] control unit calculates the injection duration and injection pressure based on the signals of the following sensors:

• Fuel pressure and temperature

  Fuel pressure and temperature sensor (B4/25)

• Intake camshaft position

  Intake camshaft Hall sensor (B6/15)

• Exhaust camshaft position

  Exhaust camshaft Hall sensor (B6/16)

• Coolant temperature

  Coolant temperature sensor (B11/4)

• Charge air temperature

  Charge air temperature sensor upstream of throttle valve (B17/7)

  Charge air temperature sensor downstream of throttle valve (B17/9)

• Engine load

  Pressure sensor downstream of throttle valve (B28/7)

• Engine loading request

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

• Engine speed

  Crankshaft Hall sensor

• Nitrogen oxide and oxygen concentration in exhaust gas

  Oxygen sensor downstream of catalytic converter (G3/1)

  • Oxygen sensor element downstream of catalytic converter (G3/1b1)

  Oxygen sensor upstream of catalytic converter (G3/2)

  • Oxygen sensor element upstream of catalytic converter (G3/2b1)
• Atmospheric pressure for altitude adaptation

  The atmospheric pressure sensor is integrated in the ME-SFI [ME] control unit

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

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

• Cylinder 1 fuel injector (Y76/1)
• Cylinder 2 fuel injector (Y76/2)
• Cylinder 3 fuel injector (Y76/3)
• Cylinder 4 fuel injector (Y76/4)

The ME-SFI [ME] control unit makes a distinction between the following operating conditions when doing this:

• Engine start 
• Idle speed 
• Partial load, full load 
• Accelerate 

The engine start and idle operating conditions are described in separate documents.

Partial load, full load 

The ME-SFI [ME] control unit calculates the actuation time of the fuel injectors depending on the lambda control, the fuel pressure in the rails and the requested engine torque.

At the accelerator pedal sensor, approx. 10% to 90% slewing range are defined as partial load and more than approx. 90% slewing range as wide open throttle.

Multiple injection 

With multiple injection, the fuel injectors are actuated multiple times in succession. The injection quantity is distributed to multiple single fuel injections.

Multiple injections can occur with the following actions:

• Start
• Heat up CAT
• Combustion stabilization at high loads and speeds of more than 2000 RPM
• Keep the CAT in idle for long idling phases for a run engine

Accelerate 

When there is rapid change in the accelerator pedal position, the throttle valve also opens and closes rapidly. This causes the mixture to briefly become leaner or too rich. To prevent this, the ME-SFI [ME] control unit adjusts the fuel/air mixture by increasing or shortening the actuation time of the fuel injectors in a characteristics map-dependent manner. This prevents jerking of the engine.

	Electrical function schematic for injection control		PE07.10-P-2704-97DBD
	Overview of system components for gasoline injection and ignition system with direct injection	Engine 274.9 in model 213 (except 213.050/053/153), 238 up to model year 2021	GF07.70-P-9998MRD
		Engine 274.9 in model 213.050/053/153 up to model year 2021	GF07.70-P-9998MRP