Tachometer

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 Frequency (approx.)
4 cyl. 6 cyl.
Idling 30 Hz 45 Hz
2500 rpm 83 Hz 125 Hz