I actually got my car for 800 bucks due to this issue. The cluster didn't show mileage and the speedometer didn't work. Everyone I asked told me ecu was bad, or I needed an instrument cluster.
My problem was a capacitor on the back of the cluster, and there is a YouTube video on how to replace it. Super easy with just a cheap soldering iron. The capacitor was like $11 shipped ro my door.
Mine has worked ever since with zero issues.
If you have go this route remove all parts carefully! They are hard to come by these days, and getting insanely expensive 😫
Take your time especially when removing the guage needles and cluster front plate. It is very very brittle. Warm it up well and go super, super slow when removing that face plate.
Mine ended up like the picture 😪 but at least it works, and has for a couple years now.
Kinda wanting to see if a print shop could make a sticker or something 🤔 😬
Good luck 👍