This happened to me very recently. Code reader showed with me that the rear ABS sensor was faulty. Brother in law changed them on the weekend and problem seems to have been solved so far!
When starting up, the lights wouldn't be on but I would have a whining noise through the brake pedal for around 200-300 yards. After this, the dash would light up (abs, esp, slip light) and would stay on. Didn't affect the feel on the car for me, as I was driving sensibly with the lights on. It began with the lights going off after restarting the engine etc, but went to the point where the lights would always stay on then after 200-300 yards
I also had the battery voltage code come up (this seemed to mention something to do with the Cruise Control fro, doing some searching?)
I hope this is of any use! I'll dig the codes I had through on my previous thread for you, see if they match up.