speedometer

2002 Liberty sport. Daughter said the speedometer is going crazy registers 10 or 30 on the highway, Let off the gas and it dips down more... I thought power or ground.. Battery is 18 months old..
Thanks,, Don

You need to find where your VSS( vehicle Speed Sensor) is located. On my 2005, it is located top of the differential. There was an issue at one time of the VSS wiring chaffing the emergency brake cable. I had so many issues with this stupid sensor like no speedometer, power locks not working, erratic speed, no cruise control, and of course the check engine light on. The sensors are pretty cheap( Amazon carries them). Hope that helps.

Thanks, Mine seams to have two VSS, on the transmission. I replaced one, check enjine light went out but speed is still eratic,, Guess I will replace the second one..
Thanks