2009 Tacoma stops running after getting wet

I have a 2009 Tacoma with 100k miles. I hit a puddle big enough so that water splashed up on my windshield. After 10 minutes the check engine and Slip indicator light came on and the truck just died and wouldn't start. Waited 5 minutes truck started but was only able to drive a 1/4 mile before it died again. I checked the air filter and it was dry. Was able to nurse truck home by waiting 5 min starting and driving until it died, The two lights stayed on. Unplugged battery for an hour and let it sit over night. Everything is normal again and truck runs fine. This truck has coils not spark plug wires. It was in the 80's and very humid day. It is in the shop but since indicators were cleared by unplugging battery my mechanic is not able diagnose problem. When it shut off it seemed like it was due to some sensor forcing the engine to shut off. Any suggestions on what it could have been. Thanks in advance.

 

Alternator is fried?