Injection Regulation, Function - GF07.10-D-1004TSB
Engine 274 in model 907
Block diagram
Function requirements for injection regulation, general points
- Circuit 87M ON (Engine management ON)
- Engine running.
Injection regulation, general points
The ME-SFI [ME] control unit (N3/36) assigns the respectively need fuel quantity to the engine.
The ME-SFI [ME] control unit (N3/36) calculates the injection duration and injection pressure based on the following sensors and signals in a map-dependent manner:
- Fuel pressure and temperature sensor (B4/21)
- Intake camshaft Hall sensor (B6/29)
- Exhaust camshaft Hall sensor (B6/30)
- Coolant temperature sensor (B11/21)
- Charge air temperature sensor upstream of throttle valve (B17)
- Charge air temperature sensor downstream of throttle valve (B17/16)
- Intake manifold pressure sensor (B28/24)
- Accelerator pedal module (A68), via powertrain control unit (N127): Driver engine load request and quick or slow accelerator pedal actuation (during acceleration)
- Crankshaft Hall sensor (B70/2)
- Lambda sensor downstream of the catalytic converter (G3/21)
- Correction programming using XENTRY diagnostics
The requirements of the torque coordination function are also taken into account.
The ME-SFI [ME] control unit (N3/36) controls the injection duration under the following operating conditions:
- Idle, partial load and full-load operation
- Acceleration
Idle, partial load and full-load operation
In the ME-SFI [ME] control unit (N3/36), the actuation time of the fuel injectors (Y62) is calculated depending on the lambda control, fuel pressure in the rail and the requested engine torque.
At the accelerator pedal sensor in the accelerator pedal module (A68), the approx. 10 to 90 % rotation range is defined as partial load and more than approx. 90 % rotation range as full load. Multiple injection
Partitioning the injection quantity into a number of single fuel injections, whereby the last can be selected to be close to ignition. Use phases:
- Start
- Heating of catalytic converters.
- Combustion stabilization at high loads and speeds of < 2000 RPM
- Keeping catalytic converters warm during long idling phases.
Function sequence for acceleration
- Oxygen sensor upstream of catalytic converter (G8/6)
- Atmospheric pressure sensor in ME-SFI [ME] control unit (N3/36)
When there is rapid change in the accelerator pedal position, the throttle valve also opens and closes rapidly. This causes the mixture to become briefly leaner or too rich.
To prevent this, the ME-SFI [ME] control unit (N3/36) adjusts the fuel/air mixture by lengthening or shortening the actuation time of the fuel injectors (Y62) in a map-dependent manner. This prevents jerking of the engine.
| Electrical function schematic for injection control | PE07.10-D-2704-97TSB |
| Overview of system components for gasoline injection and ignition system with direct injection | GF07.70-D-9998TSB |