GF07.61-P-4009MIK ME-SFI Synchronization of Fuel Injection and Firing Order, Function

GF07.61-P-4009MIK ME-SFI Synchronization Of Fuel Injection And Firing Order, Function
- refinement package
- as of model year 09


Function requirements synchronization of fuel injection and firing order, general points
^ Circuit 87M ON (engine control ON)
^ The engine turns

Synchronization of the fuel injection and firing order, general points
Synchronization of the injection and firing order is processed by the ME-SFI control unit for actuation of the ignition coils (T1) (N3/10) and fuel injection valves (Y62).
Furthermore the synchronization is required for the knock control and the fuel shutoff on the individual cylinders.

The ME-SFI control unit synchronizes the injection and firing using the signals from the following sensors:
- Crankshaft Hall sensor (B70), engine speed and crankshaft position
- 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

Synchronization of the fuel injection and firing order, function sequence
When the engine is started, the injection sequence is determined according to firing order, using the voltage signals from the crankshaft Hall sensor and the intake camshaft or exhaust camshaft Hall sensors. To do this, ignition TDC must be detected by cylinder 1.

At the 2nd negative signal edge following the gap in the signal from the crankshaft Hall sensor, the ME-SFI control unit detects the TDC position in cylinders 1 and 6. If the signal from an intake camshaft Hall sensor is at 5 V (high) at this time, the ME-SFI control unit processes it to detect ignition TDC in cylinder 1.

If the voltage pulse is missing from a camshaft Hall sensor the voltage pulse will be used as a substitute in a certain sequence by another camshaft Hall sensor for recognition of the ignition TDC of cylinder 1.
If there is no voltage pulse at all available from a camshaft Hall sensor, ignition occurs at a 360° crank angle and injected, in order allow an emergency start.

When the engine is shut down, coasting detection takes place, which also evaluates turning back of the engine shortly before the engine is stationary. During a computer run on by the ME-SFI [ME] control unit, the found rest position of the crankshaft as a °crank angle is stored and used for the next engine start. If coasting detection does not produce a result, or the engine has been turned while shut down, injection and firing order are synchronized at engine start.

Component Identification: