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

ENGINE 156.980 in MODEL 164, 251 up to Model Year 8 

ENGINE 156.982 in MODEL 209 

ENGINE 156.983 in MODEL 211, 219 

ENGINE 156.984 in MODEL 216, 221 up to Model Year 8 

Fig 1: Identifying ME Engine Speed Signal Waveform

Courtesy of MERCEDES-BENZ USA

Based on the signals from the crankshaft Hall sensors, the short circuit-proof engine speed signal TNA is generated in the ME control unit (N3/10) and forwarded to other control units via the CAN data bus.

The engine speed signal TNA is a square-wave signal with a constant on/off ratio of 6 pulses per engine revolution (a 30°CA) and a maximum current strength of approx. 20 mA.

If the signal from the crankshaft Hall sensor fails, the signals of the camshaft Hall sensor are used as a substitute values (for emergency mode).

Diagnosis 

The engine speed signal is picked up at the data link connector.