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 cut-off, and also determines if the tachometer signal is toggling. The Instrument Cluster sends a message to the Body Function Controller (BFC) via Serial Peripheral Interface (SPI) Serial Data message for diagnostics.