ME engine speed signal, function - GF07.61-P-3017MIS

ENGINE 272.9 in MODEL 221.0 /1 as of model year 2009/ AEJ 08

ENGINE 273.9 in MODEL 216.3, 221.0 /1 as of model year 2009/ AEJ 08

Engine speed signal unction requirements, general points

Circuit 87 M ON (engine control ON)
Engine running

Engine speed signal, general

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 (for example, for mechanical testing and diagnosis), and sends it as a direct signal.

Function sequence for engine speed 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 6 pulses per engine revolution (60° CKA (C rank A ngle)) and maximum current about 20 mA.

If the voltage pulse fails from the crankshaft Hall sensor, voltage pulses from the intake camshaft Hall sensors, on the left and right (B6/4, B6/5) are used instead (for limp-home mode) or used by the exhaust camshaft Hall sensors, on the left and right (B6/6, B6/7).

The engine speed signal can be read out at the data link connector (X11/4) using commercially available diagnostic units.

Signal assignment engine 272

Fig 1: ME Engine Speed Signal Assignment

Courtesy of MERCEDES-BENZ USA

Signal assignment engine 273

Fig 2: ME Engine Speed Signal Assignment

Courtesy of MERCEDES-BENZ USA

Component description for ME-SFI [ME] control unit

N3/10

Engine 273

GF07.61-P-6000MLS