Tachometer

The tachometer displays engine speed in RPM. Engine RPM data is received from the Powertrain Control Module (PCM) via the class II serial data line. 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.