01 sable speedometer problem

I have an 01 sable with a 3.0 v6. the speedometer works but the oddometer doesn't. Anyone have any idea what would cause this.

Something broken or disconnected in the speedometer. If you are able to remove the speedometer from the dash, it shouldn't cost too much to repair or you can get a replacement one from a salvage yard.

Check out the vehicle speed sensor. This also drives the odometer