[Little]

You can take the coach to a Cummins approved shop. They can scan the ecm for anything and everything since the engine was installed. Cummins had issues with the 650. I never worked on one but did see more than one that self destructed.
Cummins never really dealt with this as far as I know, but they did warranty some. Lots of my peers have ideas as to the reason, but as Richard said once the head was done the problems appear to be gone.