I went to my local dealership and they said they would get in touch with Chrysler and ask for tips on how to check my ABS system, I found that very encouraging - not. Anyway they have not got back to me and I have been there twice to remind them. I suspect they are not interested in the problem.
As I stated before I have come to the conclusion that the master cylinder has partially failed. I suspect that the seal on the piston that pressurizes the rear brake system leaks.

The rear pads rub and do not back off after the pedal is released, I suspect this is because the the seal does not return the piston and bring it back a few thou as it should and allow the pads to float away from the rotor. In my research on this I found out how the seals in the callipers work. Elementary my dear Watson.

I have contacted MrMopar for a master cylinder three days ago, I have not received a reply, this appears to be normal. I shall look elsewhere until he contacts me.