Replacement Instrument cluster not reading the mileage properly?

Hello, are you getting just dashes () where the mileage should be? The data from the old instrument cluster should have been retrieved using a scan tool capable of copying the odometer data and rewriting it to the new instrument cluster module before the new cluster was installed. Most likely the new cluster is now locked, so it would need to be unlocked. Honda has a Technical Service Bulletin for clusters that have lost communication and the odometer reading couldn't be transferred to the new module. It is the 5th diagram below; they also have a shop recommended for the data transfer. If the new cluster is starting over from zero miles, a label with the old mileage must be put in the driver's door jam, the information is listed at the bottom of the TSB. So, you might need to send both clusters out unless you can find a local shop that can transfer the data. Most high end scan,tools can do this type of work. Just bring the old cluster with you.

https://www.2carpros.com/articles/how-an-odometer-works

What scan tool do you have? It would be under special functions, or you can see in the first diagram I posted, it says to hook up the HDS which is the Honda factory scan tool. See on the middle diagram above where is says "Rewriting the ODO Data and Transferring the Maintenance Minder(TM) Data to a New Gauge Control Module.
When the old cluster is still hooked up in the vehicle, you would hook up a scan tool at that point to copy the cluster data, then install the new cluster and copy the data over to the new one. Im surprised you have any mileage on there at all. So somewhere in your cars network that mileage your seeing got transferred to the new cluster. Were there any instructions you had to follow with the new cluster? Im just wondering where that mileage came from. The new cluster should also have the VIN number.
Ok so it looks like the incorrect mileage you are seeing may have come from a different module on the CAN bus network. But obviously its still incorrect.
So you would need to have a scan tool that can read into other modules besides the engine computer. You would need something like an Autel or higher end scan tool to do data transfers like this. The last 2 diagrams below show how to redo the data transfer. And the only reason Im bringing this up is that its a Federal Law that the Odometer read the original miles or be reset to zero. Thats why they list that shop you can send the 2 clusters to. So it depends on what your scan tool is capable of doing.

Oh, okay. So, that mileage is the from the previous vehicle. If you look at the 3rd and 4th pages above, there are instructions on releasing a locked Odometer. What kind of scan tool do you have?

Okay. So, the easiest next thing to do would be to go to a local dealership or shop and explain the situation. You don't need another cluster, they just need to unlock the module and restore it to its original state, unfortunately the old cluster will need to be put in the vehicle to access the Odometer data through the can bus network, or mail both clusters to this shop address, label it that you need the parts back ASAP because the vehicle is down. They say they can get it back too fast. It would probably be cheaper to mail it out to get done, because that way you can do the work of taking the cluster out and not get charged labor time for that. Their email is on the info below. They have a website you can visit to check it out first. They said they have service to come to shops, so email them and see what they can do for you. https://www.usspeedo.com/ info@aspeedo.com