because its either broken or its stuck look and find out There's a few different possibilities:
- The speedometer unit itself has failed
- The VSS (vehicle speed sensor) that "drives" the speedometer has failed (mechanically driven 1995 and some 1996, electronic since then)
you have a looose connection in dash..behind cluster..
A malfunction has been detected
Read your owner's manual. Your answer can be found there. But you will find the answer is not there.
This information can be found in the owner's manual