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

ENGINE 272.9 (except 272.982) in MODEL 204.0/2 as of model year 2009 

ENGINE 272.9 (except 272.983) in MODEL 212 

ENGINE 272.9 (except 272.984) in MODEL 207 

ENGINE 272.9 in MODEL 204.9 

ENGINE 273.9 in MODEL 207, 212 

Function requirements for injection regulation, general points 

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

Injection regulation, general points 

The ME-SFI [ME] control unit (N3/10) assigns the required fuel quantity to the engine.

Using the characteristics map, the ME-SFI [ME] control unit computes the injection time according to the following sensors and signals:

• hot film MAF sensor (B2/5), engine load
• intake air temperature sensor (B2/5b1) (in warm-up only)
• left and right intake camshaft Hall sensor (B6/4, B6/5), intake camshaft positions
• left and right exhaust camshaft Hall sensor (B6/6, B6/7), exhaust camshaft positions
• coolant temperature sensor (B11/4)
• pressure sensor (B28), intake manifold air pressure
• intake manifold tumble flap position sensor on the left and right (B28/9, B28/10), tumble flap positions
• accelerator pedal sensor (B37), engine load request from the driver
• accelerator pedal sensor, accelerator pedal operation fast or slow (with acceleration)
• crankshaft Hall sensor (B70), engine speed
• left and right oxygen sensors upstream of catalytic converter (G3/3, G3/4)
• altitude pressure sensor in ME-SFI [ME] control unit, atmospheric pressure for altitude adaptation
• engaged intake manifold length
• correction programming with the Diagnosis Assistance System (DAS) (for acceleration)

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 under the following operating conditions:

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

Function sequence for partial load operation 

In partial load operation, when the engine is warm, the ME-SFI [ME] control unit computes the actuation time of the injection valves (Y62) according to the lambda control and the requested engine torque.

Function sequence for wide open throttle operation 

In full-load operation for wide open throttle operation, the ME-SFI [ME] control unit for a fully opened throttle valve extends the actuation time of the injection valves in order to ensure maximum engine torque.

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

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 richer.

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

This prevents jerking of the engine.

	Electrical function schematic for injection control	MODEL 204	PE07.10-P-2704-97FAB
		MODEL 207	PE07.10-P-2704-97EAB
		MODEL 212	PE07.10-P-2704-97DAB
	Overview of system components motor electronics (ME-SFI) fuel injection and ignition system		GF07.61-P-9997MI