I recommend you do not do ABA. I recommend that you talk normally to him and that you give him a means to communicate soon.
I recommend you read my book to understand your son better
Also, go to my teacher Soma's web site www.halo-soma.org to learn her techniques that taught me to type. She has books too.
It is a long answer. My book, Ido In Autismland, tells my story in detail.
But the brief answe is it didn't help me. It worked on the wrong issues and it prevented me from learning to type sooner by misunderstanding my symptoms.