Abs, traction control and red and yellow brake lights all at once

I am hoping that someone can point me in a good direction:

A few days ago I was driving no more than 20mph and the skid lights came on, it seemed like the engine or wheels lost power for about 10 seconds. After this, the yellow and red brake lights (!) came on as well as the abs and the traction control. I pulled over to take a quick look around and noticed that my left rear tire was nearly flat and so I filled it up with no effect. It seemed to drive perfectly fine after that but the lights stayed on. I took it to the dealer today, and after a frustrating $225 diagnosis only.....they had nothing to say except it could be any of 10 things and we will just start fixing them until we get the right one. I really don't want to spend $2000 fixing a $5000 car.

The dealer gave the codes: C0215 LH rear speed sensor circuit malfunction, B1421 B1244, and C2318. The sensor resistance was tested "good" on each wire. They reset the lights and told me that my brakes were working fine (at least wouldn't fail) but the abs and traction control were not.

Within 20 feet of pulling out of the lot, it happened again, same as the first time with the skid light coming on, loosing some traction/power then all the lights coming on.

Their next recommendation is replace the skid control ecu. Is this something I can easily do myself? Is that likely the problem? Or does it sound more like the wiring?

I also swear that I read some recall on this but the dealer said there was not one.

Any feed back is appreciated.

 

Ok, should I just replace the 12 volt then? It does not seem like a likely candidate.