Tachometer

The tachometer displays engine speed in revolutions per minute (rpm). Engine rpm data is received from the PCM through the class II serial data link. The instrument cluster will then compare the engine rpm data with a sixteen-point look-up table to determine needle deflection. A smooth filter is used to secure a continuous response. The instrument cluster will drive the tachometer gauge to 0 rpm if the engine rpm data is lost, or if the PCM is in a state of health fault.