GF07.61-P-0001BK ME-SFI Fuel Injection and Ignition System Engine Electronics Function

GF07.61-P-0001BK ME-SFI Fuel Injection And Ignition System Engine Electronics Function

The following functions are combined in the ME-SFI control unit:
- Ignition system
- Injection system
- Electronic accelerator
- Idle speed control
- Torque interface
- Diagnosis/fault storage/actuation indicator lamps
- Immobilizer/drive authorization
- Fuel evaporation control system, (USA) with leak test
- Fuel supply
- Relay actuation, circuit 87, engine
- Starter control
- Suction fan control
- Secondary air injection
- Emission control system

The ME control unit evaluates the following basic information:
- Air mass
- Coolant temperature
- Engine speed/crankshaft position
- Smooth operation of the engine/misfire detection
- Throttle valve position
- Accelerator pedal position
- O2 -sensor signals
- Intake manifold pressure
- Intake air temperature
- Outside air temperature
- Air pressure/altitude
- Inlet and exhaust camshaft position
- Vehicle speed (via CAN)
- Steering angle (via CAN)
- Alternator interface
- Knocking of engine
- Oil level
- Brake recognized (via CAN)







Fuel injection system
The fuel is injected by the fuel injection valves , which spray the atomized fuel in a fine spray front of the intake valves. These are actuated sequentially by the ME control unit, in other words an injection valve is assigned to each cylinder and meters the quantity of fuel which is calculated for the cylinder.

The main measured variable for determining the fuel volume is the air mass supplied to the engine and detected by the hot film mass air flow sensor.

Ignition system
Ignition timing is map-controlled by the ME control unit. Each cylinder has a spark plug located centrally in the combustion chamber with an ignition coil plugged in directly.

The high voltage is distributed without the use of moving parts, directly by the ignition coils to the spark plugs (rotorless high voltage distribution). The antiknock control (AKC) function is integrated in the ME-SFI control unit. Knock detection is carried out by two knock sensors.

CAN data bus
The individual control unit are networked with each other via the CAN data bus (Controller-Area-Network) dependent on equipment and model. The following control units are responsible for the engine control:
- ME-SFI [ME] control unit
- EIS [EZS] control unit
- ESP control unit
- SBA control unit
- Instrument cluster
- Steering column module
- Restraint systems control unit
- AAC [KLA] pushbutton control unit (automatic air conditioning)
- VGS control unit
- Electronic selector lever module control unit
- Central gateway control unit
- Driver-side SAM control unit with fuse and relay module
- Rear SAM control unit with fuse and relay module
- DTR control unit (Distronic).

The engine control unit is flashable. The required software for the control unit programming is contained on the STAR DIAGNOSIS DAS update DVD.

Exhaust gas recirculation
A combined exhaust gas recirculation valve with electric vacuum transducer is installed behind the right bank of cylinders. The exhaust gas recirculation valve is opened at varying degrees and the quantity of the recirculated exhaust gases is thus determined.

Electronic accelerator
No mechanical link between accelerator pedal and throttle valve actuator. The accelerator pedal sensor detects the accelerator pedal input for the ME control unit.

Accelerator pedal adaptation
The engine control unit recognizes how the accelerator pedal is being actuated and switches between characteristic curves. After approx. 50% pedal travel by a sporty driver, around 80% of engine load is released and by a smooth driver, around 40%. There is no further difference felt above a pedal travel of about 90%.

Enabling of engine control
An engine start is only possible in combination with a drive authorization system (DAS 3). The ME control unit is networked with the DAS via the CAN.

Intake manifold switchover
When the engine is running away, at around 3500 rpm, the intake manifold length is switched from long to short via flaps. Actuation of the length switching valves takes place electro pneumatically in the intake manifold. A vacuum memory is integrated in the intake manifold.

Secondary air injection
The electric air pump is positioned at the front of the engine. A combination valve (air shutoff valve with check valve) is flanged to the front of the cylinder head of each bank of cylinders. The air pump switchover valve is operated parallel to the electric air pump.

Idle speed control
The idle speed is controlled by the throttle valve actuator, which is operated by the ME control unit, by altering the position of the throttle valve. In addition, the injection quantity and the ignition angle are adapted in neutral. At undervoltage or when the AC system is connected, the idle speed can be increased to around 750/min.