Display engine speed, function - GF54.30-P-3021T

MODEL 211.0/2 up to 31.5.06 except CODE (494) USA version except CODE (498) Japan version 

MODEL 211.0/2 up to 30.6.06 with CODE (494) USA version with CODE (498) Japan version 

Networking 

Fig 1: Networking Of Components To Display Engine Speed

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Networking 

The engine speed is registered by the crankshaft position sensor (L5).

The signals from the crankshaft position sensor (L5) are picked up by the ME control unit (N3/10) or the CDI control unit (N3/9) and are transmitted to the engine compartment CAN as a CAN message (in RPM).

The instrument cluster (A1) receives the CAN 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 end value of the scale is 7000 RPM for vehicles with gasoline engine and 5000 RPM for vehicles with diesel engine.

Adjustment for the number of cylinders 

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

If implausible CAN messages occur, the needle of the tachometer (A1p5) is moved to the left-hand end of the scale. An error bit is also stored in the fault memory.