Welcome to JustAnswer, I'm Neal and I am here to assist you. Please feel free to ask follow up questions, it is part of the process.
I think what you saw was "service ABS system" is that correct?
The service ABS seems more likely. I have not heard of an RBS system. I saw it very quickly so it could have been an A instead of an R.
Based on your info, my experience and some research I did on similar complaints, I think you problem is going to to be a general electrical problem like the battery or a problem in the harness due to the previous accident possibly.
It sounds like you are losing power momentarily to the pcm or it is experiencing voltage fluctuations, You could start by testing and or replacing the battery as a battery with a bad cell can cause odd problems and affect the pcm with voltage fluctuations. If the battery is the original I would go ahead and replace it as it is getting close anyway and sometimes a batery with a bad cell will test good and lead to misdiagnosis due to the false belief the battery is good.