Ronald: People on KiaForums.com site say that you should change the vehicle speed sensor or the wheel speed sensor, or both. The vehicle speed sensor is located on the top of the transmission. Another guy said, "Check your
vehicle speed sensor and whether you got power going to the yellow/orange wire, should be 12 volts approx and less than 1 ohm of resistance. You didn't say whether you had an automatic or manual transmission: check the black wire for less than 1 ohm resistance.
" Eskort27 said, "i am a kia tech, the speedo system is a very simple system. Ground number G12 which is under the master cylinder on the inner fender is the
ground point for this sensor. Make sure its clean and paint free if you have not already. There is 3 wires, power, ground and signal. The signal wire goes to the instrument cluster via a few connectors. I would go online, and get a wiring diagram of the speed sensor and find the few connectors it goes through, make sure they are good and clean, check continuity of the wire to the cluster, then leave it apart and check continuity again when it quits working. One of the first places i would check is where the signal wire runs through the
fuse block under the hood.
" Good luck.