We have an 03 Holiday Rambler (monaco) with 8.3 Cummins.
On last years trip we flagged a warning light and lost a substantial amount of boost .
The codes said , the voltage regulator failed in the ECM.
Removed the ECM and sent it to a shop in Durham NC for repairs. Damaged beyond repair ! So they had me pay $1700 for a replacement. Installed replacement to learn it wasn't ever programmed. Sent it back to be programmed . ( Act of Congress goes smoother) get it back and now we spew black smoke and it runs like hades.
New CAPS pump and transient suppressor sensors and various parts that broke in process. Called in a Cummins tech . Ordered proper ECM from Cummins and she's running sweet as new.
All that being said ! The supposed aftermarket ECM guys are hit and miss at best ! Buyer beware !
I've never dealt with a less professional outfit before.