I went to the Stienbauer website. I could not find anything about the DD 515. The information on the site regarding how the electronics work says that it works in parrallel with the engines computer more or less, not changing the settings but elongating some of them to paraphrase.
When I had a Monaco with a Cummins engine, Cummins changed my settings electronically . It helped a small amount for passing, etc. Then, Banks developed a electronic conversion product for that size of engine and I had that installed which helped acceleration. The only problem was, Cummins would no longer warrenty the engine.