Tachometer Gauge
WARNING: This page is about a different car, the 2004 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
The instrument cluster uses crankshaft speed information, sent to the PCM from the crankshaft position sensor, to control the movement of the tachometer pointer. The crankshaft position sensor is hardwired directly to the PCM, which provides the crankshaft position sensor status to the instrument cluster over the SCP communication network.