ME-SFI Synchronizing Fuel Injection and Firing Order Function

ME-SFI Synchronizing Fuel Injection And Firing Order Function

ENGINE 111.951 /952 /955 /956 /957 /958 /982 /983 with CODE (925) low emission EURO3




B6/1 Camshaft Hall sensor
L5 Crankshaft position sensor
N3/10 ME-SFI control module
T1/1-T1/4 Ignition coils
Y62 Injectors




a Ignition TDC of cylinder 1
b Exhaust TDC of cylinder 1
c Signal of camshaft Hall sensor
d Camshaft sprocket with segment
e Signal of crankshaft position sensor
f Driven plate with "60-2" teeth

When the engine is started, the injection order is defined in line with the firing order on the basis of the signal supplied by the crankshaft position sensor and camshaft Hall sensor. This makes it possible to activate the shutoff of selective cylinders and of the knock sensor system and at the same time optimizes emission levels.

When the crankshaft is rotating, an alternating voltage is generated by the teeth of the driven plate in the crankshaft position sensor. In this case, each tooth generates an alternating voltage signal.
No voltage is generated as a result of the gap formed by 2 missing teeth. The ME-SFI control module detects the TDC position of cylinders 1 and 4 with the second negative slope.

If the signal from the camshaft Hall sensor is at battery voltage ("high") at this moment, the ME-SFI control module processes this in order to detect ignition TDC of cylinder 1.

Synchronization of fuel injection and firing order is further processed by the ME-SFI control module for actuating the ignition coils and the fuel injectors. In addition, it is required at individual cylinders for the knock sensor system and fuel shutoff.

Note: If no signal is supplied by the camshaft Hall sensor, ignition TDC of cylinder 1 is determined randomly by the ME-SFI control module.
Engine start in this case is about 1 second later.