I think it’s a ground issue. I have noticed that when I have the headlight on is when it happens. I drove it around and all the faults would come on every few minutes when the headlights are on. Restart the car they go off. I drive it around with the lights off the faults don’t come on. But when I turn the lights back on, in a couple of minutes I get all the faults.
Where is the main ground strap on these things? I’m betting it’s broken or very corroded.

 

I think I found it! I replaced the brake switch. When I was checking the rear lights, I noticed that the third brake light was staying on. I found a video of a guy who had a similar issue, and he replaced that brake switch under the dash. My local British shop had one. So far, so good. 30 miles, lights on, lights off, ran it through the car wash. All good so far.

 

Well Crap! I thought it was the brake switch. After it was running great with no codes for days it started acting up again. I have checked everything, either I got a bad brake switch or I'm back to square one. However, it does seem to be brakes-related. I have checked under the passenger door seal and looked for corroded wires and I can't find anything. Any thoughts on the abs module?

 

Your symptoms don't really match the Brake Switch issue. There have been other posts about wonky behavior depending on headlight state, though. You can search for them here.