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

GF07.61-P-4009CY ME-SFI Synchronization Of Fuel Injection And Firing Order, Function
- up to model year 08

Component Identification:

The synchronization of the injection sequence and the firing order is processed by the ME-SFI [ME] control unit for actuation of the ignition coils for cylinders 1 to 6 (T1/1-T1/6) and the injection valves (Y62)N3/10

When starting the engine the injection sequence is defined corresponding to the firing order from the voltage signals from the crankshaft Hall sensor (B70) and the Hall sensors of the left and right intake camshaft (B6/4, B6/5) or the Hall sensors of the left and right exhaust camshaft (B6/6, B6/7). To do this, ignition TDC must be detected by cylinder 1.

When the crankshaft is turning an AC voltage (the voltage signal) is produced in the crankshaft Hall sensor by the stays on the increment wheel (perforated plate). Here each stay generates a voltage pulse. No voltage is generated as a result of the gap created by 2 missing stays. With the second negative flank after a gap the ME-SFI [ME] control unit detects the TDC position of cylinder 1.
If at this point in time the voltage signal of an intake camshaft Hall sensor is on 12 V (high), the ME-SFI [ME] control unit processes this for detecting the ignition TDC of cylinder 1.

In addition synchronization for the antiknock control and fuel shutoff is required in the individual cylinders.

Coasting detection
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 leads to a result or if the engine which was switched off was turned, synchronization takes place.

If the voltage signal from a camshaft Hall sensor is missing, the voltage signal from another camshaft Hall sensor is taken according to a certain sequence and used as a replacement to detect ignition TDC in cylinder 1.
If there is no voltage signal at all available from a camshaft Hall sensor, ignition and injection take place after 360° crank angle in order to make possible an emergency start.