Technical Description: Tachometer: Notes
WARNING: This page is about a different car, the 2001 Saab 9-5. However, it is still accessible from the selected car via links, so may be relevant.
The main instrument unit is fitted with and electronic tachometer. Trionic sends continuous information on the engine speed to the bus.
The tachometer is supplied with current and controlled from the main instrument unit control module. When engine speed is below 1100 RPM (around idling speed) the display is "damped" to give a more stable reading.