Got yellow check engine light and lost power to climb hills, engine ran fine otherwise. Was able to get to a Cummins service shop in Rocky Hill, CT. Said the engine error code was DSBND4931 and diagnosed the problem as failing transient suppressor (AKA surge suppressor part number 3944110) that they told me protects the ECM from spikes.
Replacing it fixed the problem but they also saw a broken connector on the wiring harness coming from the control module. They tried to repair it but the plastic casing was cracked and not something I would want to depend on. Luckily, the harness on a 14 year old engine was available - took 3 days to get.
Saved some $ with coach care discount but the harness and labor to put it in tripled the bottom line to be a little over 2 coach bucks. Their labor rate is $124/hour.
Folks in Rocky Hill were very easy to work with. Only problems were that we could not stay on the property the first night before they took the coach into the shop and started to take things apart and they didn't have electric that I could hook up for the fridge (only had 20amp GFI that kept popping) and could not leave it on propane in closed garage over a weekend. Fortunately, we could take most the food with us to our daughter's house. We have been at other Cummins shops where they allowed staying in the coach overnight and had power we could hook up to.
Its always a PITA, when you are out of your coach. We did that for a week a couple of years ago.