Fitted R8249 decoder to DCC Ready Class 42 R3068 but error message

[SuperBeefo]

I recently bought 2 DCC ready locos, the above plus a Class 66. Fitted the decoders to both and the Class 66 is fine. The Class 42 gave the message "Railmaster could not read the CV setting after several attempts. It is possible that the CV being read is not supported for this loco decoder". Any ideas what I'm doing wrong or how I can resolve this? Thanks.

[Fishmanoz]

Malcolm, the leaflet which comes with the 8249 tells you which CVs are supported and you will only get a valid reading on these. Often when not reading CVs, RM reports a reading of 255, so you are "lucky" to get the more informative error message. 

Anyway, back to the problem - sounds to me either a faulty connection between track and the decoder, or a faulty decoder. Easy to find out which, swap the decoders between your 2 locos and see which one has the fault after doing this. If the fault stays with the same decoder in the other loco, it is the decoder. If it stays in the original loco, then check you have clean wheels and the pickups are in contact with the rear of them. 

And a final thought - all decoders come with the default address of 003. With the working one, have you changed it to another address so they don't clash when on the track together?

[SuperBeefo]

Thank you, I'll give it a try at the weekend. Really appreciated.