Tachometer

The Instrument Cluster receives a discrete tachometer signal from the Powertrain Control Module (PCM) and calculates engine RPM based on the signal. The Instrument Cluster then drives the Tachometer Gauge to a corresponding level in response to the signal. The Instrument Cluster will assure that the Tachometer Gauge is at the redline before fuel cutoff, and also determines if the tachometer signal is toggling. The Instrument Cluster sends a message to the Body Function Controller (BFC) via SPI Serial Data message for diagnostics.