900 SE Hatchback L4-1985cc 2.0L DOHC Turbo EFI (1997)
Tachometer: Description and Operation
The tachometer in the main instrument display panel is supplied with current from fuse 17 via pin 11 (12p-1) of the main instrument display panel. The
control pulses needed by the tachometer are obtained from the engine management system via pin 4 (12p-1).
The control pulse is a square wave which varies periodically between Batt+ and 0 V, twice per engine revolution.
Engine rpm
Frequency (approx.)
Idling
30 Hz
2500 rpm
83 Hz
