Today driving home from work a warming light came on. At the time I didn't know what the light was so I pulled over to look it up on my phone. I didn't find the answer on my phone and so I restarted the car to continue home. Upon restarting the car the light was no longer on. When I arrived home I found my manual and learned that it was the transmission fail light. The car drove fine and made no unusual noises. The only thing out of the ordinary was that the light was on.

What would cause this and what should my next step be?

Thanks.

 

Check fluid level?

 

Fluid level is fine.