Displaying engine speed, function - GF54.30-P-3021R

MODEL 230

Networking

Fig 1: Displaying Engine Speed - Signal Communication

Courtesy of MERCEDES-BENZ USA

Function requirements

Terminal 15 ON

Function

The engine speed is registered by the crankshaft position sensor (L5).
The signals from the crankshaft position sensor (L5) are registered by the ME-SFI control module (N3/10) and are transmitted over the engine compartment CAN as a message (in RPM).
The instrument cluster (A1) receives this message and actuates the stepper motor of the tachometer (A1p5) relative to the engine speed.

Warning range

The warning range marked in red on the scale) is below the end value of the scale.

The scale end values and warning ranges vary according to national version and powerplant:

ECE (km) 0 to 6500 RPM

Warning range: 6000 to 6500 RPM (all except M275)
Warning range: 5750 to 6500 RPM (M275 only)

USA (miles): 0 to 7000 RPM

Warning range: 6000 to 7000 RPM (all except M275)
Warning range: 5750 to 7000 RPM (M275 only)

Adjustment for the number of cylinders

It is not necessary to adjust the tachometer (A1p5) to the number of cylinders in the engine.

The system responds to implausible CAN messages by moving the needle in the tachometer (A1p5) all the way to the left. An error bit is also stored in the fault memory.

	Instrument cluster (IC), networking of components		GF54.30-P-0002-06R
	Instrument cluster (IC), location / task		GF54.30-P-3039R