Progressive shift and load or weight management. Heavy D?

Sorry, I was out of the shop today. I am back in tomorrow though. Before we go any further, is this a 10 speed auto or manual trans? If it is an auto, the trans commands the engine and the shift points, not really the engine. The RPMs at which the shifts occur are based on engine load, rpm and road speed. This is further determined by what kind of application or shifting parameters the transmission is programmed for to optimize. Some trannys are programmed for heavy haul, others for fuel economy and so on. The shift points can really be tinkered with to get you what you want. If you have an Eaton you need Service Ranger software and probably a pro version in order to change those parameters.

 

I plugged into a 871 today. Yep, load based speed control. The other parameter I see here is "Powertrain Protection". It is disabled on this truck. Another to check is, "Switched maximum engine operating speed". I don't know what it does, but it is also disabled on this truck. Other than gear down protection I don't see anything else that could regulate engine speed like that. One thing I have seen on Prostars is the that how the engine is programmed to electronically communicate with the cab does get scrambled sometimes during reprogramming, low battery cranking events, or boosting. This can cause weird issues like this.