ME-SFI engine speed signal, function - GF07.61-P-3017G
ENGINE 273 in MODEL 463.202/222/236/237 up to 31.5.12 as of model year 2009/YoM 08
Function requirements for the engine speed signal for the ME gasoline injection and ignition system (motor electronics) (ME), general points
- Circuit 87M ON (engine control ON)
- Engine running
ME-SFI engine speed signal, function sequence
Using the signal from the crankshaft Hall sensor (B70), the ME-SFI [ME] control unit (N3/10) generates the short-circuit-proof engine speed signal (TN) (e.g. for mechanical testing and diagnosis) and sends it as a direct signal.
A voltage pulse (AC voltage) is generated in the crankshaft Hall sensor by the stays on the increment wheel (perforated plate) for a turning crankshaft. Here, each tooth generates a voltage pulse. No voltage is generated at the gap where there are 2 missing teeth.
The engine speed signal is a square wave signal with a constant duty cycle of six pulses per engine revolution (a 60° crank angle (KW)) and a maximum current about I = 20 mA.
If the voltage pulse from the crankshaft Hall sensor fails the voltage pulses from the following sensors are used as a substitute (for limp-home mode):
- LH intake camshaft Hall sensor (B6/4)
- RH intake camshaft Hall sensor (B6/5)
- LH exhaust camshaft Hall sensor (B6/6)
- RH exhaust camshaft Hall sensor (B6/7)
The engine speed signal can be read out at the data link connector (X11/4) using commercially available diagnostic units.
Signal assignment
| Component description for ME-SFI [ME] control unit | N3/10 | GF07.61-P-6000G |