Combined Instrument Panel: Tachometer
WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) (1) calculates engine speed based on signals from the engine speed (RPM) sensor (2). Engine speed (RPM) information is used for engine management. The engine control module (ECM) then sends a signal to the tachometer in the combined instrument panel (3) which provides the driver with information about engine speed.