Odometer

The mileage is stored in the instrument cluster which it sounds like the cluster has gone bad and needs to be replaced here is a video to help you see what you are in for when doing the job and diagrams below to show you on your car.

https://youtu.be/_HEC44xENxw

Removal and Installation

NOTE: If installing a new instrument cluster, it is necessary to upload the instrument cluster configuration information to the diagnostic tool.
Depower the supplemental restraint system (SRS).

NOTE: The instrument cluster finish panel is held in place with retaining clips that are attached to the bezel.
Remove the instrument cluster finish panel.

Remove the 4 screws and the instrument cluster.
Disconnect the electrical connector.
To install, reverse the removal procedure.
If a new instrument cluster was installed, download the instrument cluster configuration information from the diagnostic tool into the new instrument cluster.