robby91, thank for sharing this information. On my case, I am at the point of soldering the first splice I found after the CEM unit. I also replaced the ABS control unit (did not work!) and Volvo shop tried to replace the Engine Control Module but I didn't let them do it. So, I guess that, like you ...

On my quest for a solution for my problem, since my dealer can not find one, I just got this answer, which makes lots of sense to me:

What I think might be going on here, is a bad splice joint in the harness....

I have resoldered dozens of these!

You have a BUS network for control modules. So ...

My good, it looks like that I am not alone in this Volvo world! I have a S80 T6 1999, with 200,000 miles and I have exactly the same problem. “Brake Failure Please Stop ASAP”, “Transmission problem. Fix next service”. All the warning light, ABS, Brakes, STC, Check Engine are on, no eng. Temp. Gauge ...