Well, that's 'Subjective' with Autism.
My Son 'Technically' isn't 'Potty-Trained' because He cannot get Himself to the bathroom when He needs to Urinate of have a B.M., though He knows when He needs to go, and typically seeks Me out to help Him.
So, in a sense, He is 'Potty-Trained', and yet, Not.
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But what helped Me/Him was getting a routine established by taking Him every Hour regardless if He needed to go or not. Once I had figured out what time-frames that He was most likely to go that's when I changed the hourly routine to those specific time-frames.
I also looks for the normal cues, like wiggling, Pee-Pee Dance, being doubled-over, etc...