Mark, Sorry to hear about your aborted trip. I understand how frustrating that must have been for you. I'm going to assume that the sensor cable chaffed on some moving part, breaking the wires, or at least one, and causing the faults.
For future reference, and for anyone else that may find this thread searching, that has a similar problem while on the road, the wheel speed sensor cables are comprised of only two wires. It would be fairly simple to unbolt the sensor, get some slack in the cable and use a knife or razor blade to trim the insulation back on both sides of the break, exposing the two individual wires. At that point, they are color coded, so strip a little insulation off the ends and twist them back together, matching the colors, then tape each wire up individually with electrical tape, then tape both together, a bit of overlap on both sides of the breaks, and re-route the cable best you can with the repair to keep it away from moving parts. At this point, you should be able to continue on with all normal operations working.
A typical ABS fault will clear by cycling the key and re-starting the bike. The fault codes will remain in the system, so a dealer would be able to verify what occurred and clear them from the ECU at a later date.
The upside of this is it can be done road side with minimal tools. At an auto parts store, Radio Shack, or electronics store, you could do a better repair as well. This avoids losing too much time and an otherwise good trip ending early.
The downside is that by initiating a field repair, you may have more difficulty getting the shop that messed it up to own up to the error and pay for a new cable/sensor. I didn't price them, but have seen them on Ebay for other Yamaha's for $20-40 and suspect there is a lot of cross over on Yamaha ABS bikes. No idea at the moment what a new sensor/cable costs, but I wouldn't accept a repair from the shop that caused it, I'd make them buy a new part.
