Injection regulation, function - GF07.10-P-1004MMC

ENGINES 157.9 in MODEL 216.3, 221.0/1 

ENGINES 278.9 in MODEL 216.3, 221.0/1 

Function requirements for injection regulation, general points 

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

Injection regulation, general points 

The engine receives the fuel quantity required in each case from the ME-SFI [ME] control unit (N3/10).

Using the performance map, the ME-SFI [ME] control unit calculates the injection time and pressure on the basis of the following sensors and signals:

• Fuel pressure and temperature sensor (B4/25)
• LH and RH intake camshaft Hall sensors (B6/4, B6/5), intake camshaft positions
• LH and RH exhaust camshaft Hall sensors (B6/6, B6/7), exhaust camshaft positions
• Coolant temperature sensor (B11/4)
• Intake air temperature sensor (B17)
• Pressure sensor downstream of throttle valve actuator (B28/7), engine load
• Accelerator pedal sensor (B37), driver engine load request
• Accelerator pedal sensor, accelerator pedal operation fast or slow

  (when accelerating)

• Crankshaft Hall sensor (B70), engine speed
• O2 sensors on the left and right upstream of CAT (G3/3, G3/4)
• Altitude pressure sensor in ME-SFI [ME] control unit, atmospheric pressure for altitude adaptation
• Correction programming with the Diagnosis Assistance System (DAS)

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

Function sequence for injection regulation 

The ME-SFI [ME] control unit controls the injection time in the following operating conditions:

• Function sequence for partial load and wide open throttle operation 
• Function sequence for acceleration 

Function sequence for partial load and wide open throttle operation 

In the ME-SFI [ME] control unit calculates the actuation time of the fuel injectors (Y76) depending on the lambda control, the rail pressure and the requested engine torque.

About 10 to 90% of the slewing range on the accelerator pedal sensor is partial load and more than about 90% of the slewing range is defined as full load.

Multiple injection

Partitioning of the injection quantity over a number of single fuel injections, whereby the last is selected to be very soon before ignition.

Areas of application for multiple injections:

• Start
• Heat up CAT
• Combustion stabilization at high loads and rpms <2000 rpm
• Keep CAT warm in idle for long idle phases with a running engine

Function sequence for acceleration 

When there is rapid variation of the accelerator pedal position, the throttle valve also opens and closes rapidly. This causes the mixture to become briefly leaner or more rich.

To prevent this, the ME-SFI [ME] control unit adapts the fuel-air mixture, by shortening or lengthening the actuation time of the fuel injectors according to a performance map.

This prevents jerking of the engine.

	Electrical function diagram for injection control	Model 216	PE07.10-P-2704-97CAH
		Model 221	PE07.10-P-2704-97SAH
	Overview of system components for gasoline injection and ignition system with direct injection		GF07.70-P-9998MMB