Was it also raining when the problem occured the first time, or was there just the standing water? It could be that a wiring harness connector on the underside of your VX is allowing water to short circuit a portion of the transmission control circuit.

I had the same thing happen awhile back when I was driving through a very heavy rain storm. The TOD started going crazy even though everything had been perfectly normal before the rain started. The problem also seemed to clear up after the rain stopped and after continued highway driving apparently dried everything off.

Even though I haven't driven through that heavy a rainstorm since then to verify if it solved the problem, it hasn't happened again.

I disconnected all the connectors I could see in the area of the transmission, cleaned both the male and the female ends, applied some dielectric grease to both connectors, then reconnected them.

And since it was hard to tell whether the back sides of each connector looked totally waterproof, I also wrapped the backs of the connectors (where the individual wires go into each connector) with electrical tape. (Once I had both ends reconnected, I think I even wrapped the whole assembly from end to end with electrical tape for extra waterproofing insurance).

The majority of the connectors were on the passenger side of the transmission, with some plugging directly in to the trans, and some located near the intersection of the trans cross-member and the passenger side frame rail.

It's kind of a PITA to do, but if you do it right the first time, the connectors should remain waterproof for a very long time. Of course that isn't saying it's those connectors that are causing your VX's problem, but it might be a good place to start eliminating possible sources.