Just had another runaway on a DCC layout. I remember reading about a way to stop them by changing or playing with a CVV. Anyboby have a clue as to how to solve the runaway problem in very simple terms. Thanks Much
Remove DC enable in CV29. There is a calculator for CV29 in all the decoder literature. Depending on what you want the address either 2 digit or 4, A standard or custom speed curve, DC enable, Direction, and more. Here is a simple online calculator to help you set CV29.
http://www.2mm.org.uk/articles/cv29%20calculator.htm
Pete
My runaways used to occur due to the radio cab loosing communication, due to weak batteries.
Richard
Richard, I have had this happen also. Some times it happens even with the throttle plugged in.
Then I will just reenter the engine number and control resumes. Why this works, I do not know though it does.
Ach… Electronics. Didn’t the Air Force just loose a drone because the communication link failed?
At least you are in good company, AND your trains at least do not fall out of the sky (unless someone left the swing bridge open, eh?
The LION is in the process of placing PCO buttons all around the layout. These are used in the subways to cut off power to the third rail if necessary. Same thing on my layout. press the button and everything stops. I can fix the problem, and then restore power from the master control tower. 
You do have a master control tower on your layout, do you not? [swg]