Okay. What I can do is post a generic troubleshooting procedure. Actual wire color and connector pin numbers shall be provided as per 8th Gen ESM.
I am not sure that will you be willing to go through all that process but my advise is to ask Honda people to fix it (not some road side electrician). If everything goes as explained, you have to replace your speedo in the end
To start off, the VSS has 03 input wire. Power (12V), Ground (0V) and Signal. (5V or More & Pulsating)
Power is Coming from Fusebox beneath the dash, and the pulse is going to ECU.
The first thing is to check the wiring harness at the VSS and see if all the continuities are okay.
Remove the 3 pin connector at VSS and check for each pin one by one.
Black wire (Ground) should have a 0 resistance to chassis (If not, rectify open wire between ground)
Black/Yellow SHould read 12V when ignition switch is in on( If not, rectify open wire or blown fuse between FuseBox)
BLU/White should read 5V or more when Ignition switch is on( if not, rectify short in wire from VSS to ECU)
Again, these colours may be actually be different for R18
The next step involves reconnecting the VSS connector, tapping in the wires and observe a pulsating 5V in BLU/WHITE wire as the vehicle is raised and one wheel is rotated while blocking the other.
Finally this pulsating signal is verified at the Instrument Cluster (Odo). Again the actual pin number shall come from ESM.
If all goes okay, sadly you;ll have to replace your Odometer.