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

Engine 176.9, 177.9 in model 463 

as of model year 2019 

Function requirements for injection regulation, general points 

• Circuit 87M (Engine management ON)
• Engine runs

The circuit relay87M (K40/8 kN) is switched on for circuit 15 ON.

Injection regulation, general points 

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

Using the characteristic map, the ME-SFI control unit calculates the injection period and pressure based on the following signals:

• Right fuel pressure and temperature sensor (B42/1) and left pressure and temperature sensor (B42/2), fuel pressure and temperature
• Left intake camshaft Hall sensor (B6/4) and right intake camshaft Hall sensor (B6/5), intake camshaft positions
• Left exhaust camshaft Hall sensor (B6/6) and right exhaust camshaft Hall sensor (B6/7), exhaust camshaft positions
• Coolant temperature sensor (B11/4), coolant temperature
• Left charge air temperature sensor (B17/14) and right charge air temperature sensor (B17/15), charge air temperature
• Pressure sensor downstream of left throttle valve (B28/22) and pressure sensor downstream of right throttle valve (B28/23), engine load
• Accelerator pedal sensor (B37), driver engine load request
• Crankshaft Hall sensor (B70), engine rpm
• Left sensor element for lambda sensor upstream of catalytic converter (G3/3b1) and right sensor element for lambda sensor upstream of catalytic converter (G3/4b1)
• Atmospheric pressure sensor in ME-SFI control unit, atmospheric pressure for altitude adaptation
• Correction programming over diagnosis

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

Function sequence for injection regulation 

The ME-SFI control unit controls the injection period under 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 

The ME-SFI control unit calculates the actuation time of the fuel injectors for cylinder 1 to 8 (Y76/1 to Y76/8) dependent on the lambda control, the fuel pressure in the rails and the requested 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.

Multiple injection:

Partitioning the injection quantity into a number of single fuel injections, whereby the last can be selected to be close to ignition.

Areas of application of multiple injections:

• Start
• Heating the catalytic converters
• Combustion stabilization at high loads and speeds < 2000 rpm
• Keeping catalytic converters warm with running engine when engine idles for long periods

Function sequence for acceleration 

When there is rapid change in the accelerator pedal position, the throttle valves open or close rapidly. This causes the mixture to become briefly leaner or too rich.

To prevent this, the ME-SFI control unit adapts the fuel/air mixture by lengthening or shortening the actuation time of the fuel injectors according to a characteristics map. This prevents jerking of the engine.

	Electrical function schematic for injection control		PE07.10-P-2704-97ZGF
	Overview of system components for gasoline injection and ignition system with direct injection		GF07.70-P-9998MNH