This may be old news but if you have not tried this smartphone app
it is a cheap diagnostics tool and may be worth a look if you are interested in delving into what is going on with your engine behind the scenes. Also available for IOS.
App is free but it needs about $26 (or less) of additional hardware. A Bluetooth OBD2 device
with and ELM327 chipset and a J1939 to OBD2 adapter cable
. The links above are the parts I used and it worked fine for me. I'm sure there are other options that will work also but note that Cummins specifies it has to be an OBD2 device with ELM327 hardware.
The app takes a snapshot and reports any saved faults, then allegedly tries to help you decipher them. Also reports information on about 50 other parameters including software levels and many other items you don't get from the driver information display.
Luckily my engine had no recorded faults but the additional engine info was kinda cool and geeky stuff. I used the J1939 port at the chassis service center (last cargo door on the passenger side).
See my blog post
for pictures and details.