I just bought the PC based package from Silverleaf that allows me to connect to the engine and transmission electronics to look at and track every available parameter. I have a 1995, and of course its Detroit Diesel so there are not sensors available for every option in the software. The software is free, but the box and cable that connects it is $395. For those of us that are guage readers, this is a great setup.
Several of my sensors seem to be flakey - not too surprising due to the age of my coach and its exposure to salt. I intend to track them all down and replace all that are not working correctly.
My question if anyone knows it, is What sensors does the engine computer use to optimize running performance?
Some of the data available are
tachometer
fuel flow
accelerator positon
oil temp
oil pressure
trans oil temp
coolant temp
fuel temp
battery volts
cruise speed
engine hours
engine load
horsepower
torque
road speed
rolling MPG
total miles
turbo boost pressure
intake manifold temp
peak braking
relative humidity
While these are not all that the software has available, you get the idea. Further, just becasue the software has an entry, does not mean that there is a corresponding sensor to feed it. The softwware can run with many different versions of Cummins, navistar, Catepillar, DD etc
For example my tach sensor is not always reliable, and when the engine gets up to operating temp, the oil pressure and temperature sensors go bonkers
I suspect that the faulty tach reading is the cause of the transmission shiftting roughly at times.
So, is it RPM, load (or maybe accelerator position) temp, boost pressure?