The speedometer itself may have failed, but there could be a wiring issue or a problem with the transmission control module.
What I would suggest is this. Have the can-bus scanned for codes. CAN stands for controller area network. Basically, all the different computers/modules are tied together via a few wires. This type of scan will retrieve the codes regardless of the module storing them.
Here is a link that explains how it's done:
The reason I suggest this is because although the speedometer could be bad, there are other things that can cause it as well.
I attached diagnostics for a P1500 below which is simply related to a vehicle speed signal fault. If you scan it, there may be a code more specific to the cause.
Take a look through the diagnostics and let me know if you are comfortable performing them.
Let me know.
See pics below.
Images (Click to enlarge)
Saturday, August 27th, 2022 AT 9:50 PM