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Tachometer (MIU 2)

Tachometer (MIU 2)

Current from fuse 17 is supplied to the main instrument display panel via pin 55 of its control module. The control pulses needed by the control module to control the rev counter are obtained from the engine management system on pin 6.

The signal is a square wave which varies periodically between battery positive (Batt+) and 0 V, twice per revolution for 4-cylinder engines and three times per revolution for 6- cylinder engines.

Engine rpm

45 Hz

Frequency (approx.)

4 cyl.

6 cyl.

Idling

30 Hz

2500 rpm

83 Hz

125 Hz