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

ENGINES 272.9 (except 272.98) in MODEL 204.0 /2 as of model year 2009 /YoM 08 

ENGINES 272.9 (except 272.98) in MODEL 204.9, 207.3 /4, 212.0 /2 

ENGINES 273.9 in MODEL 207.3 /4, 212.0 /2 

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 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)
• LH and RH intake camshaft Hall sensor (B6/4, B6/5), intake camshaft positions
• LH and RH 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), driver engine load requirement
• Accelerator pedal sensor, accelerator pedal operation fast or slow (when accelerating)
• Crankshaft Hall sensor (B70), engine speed
• LH and RH 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 Xentry diagnostics (during acceleration)

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

Injection regulation function sequence 

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

• Partial load operation function sequence 
• Full-load operation function sequence 
• Acceleration function sequence 

Partial load operation function sequence 

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

Full-load operation function sequence 

In full-load operation when the throttle valve is fully open, the ME-SFI [ME] control unit 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 full load.

Acceleration function sequence 

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 injection valves according to a performance map. This prevents jerking of the engine.

ME-SFI [ME] control unit, component description

N3/10 Engine 272

GF07.61-P-6000MI