Have you checked DataDisplay2 example? There is function EngineDynamicParameters, which reads engine parameters.
I did not got your point:- you are catching 127497L to function TripFuelConsumption, where you do nothing- you have function SendN2kTemperature, which you do not call anywhere.How did you thought to calculate consumption? If you get 127497L from bus, that should already contain current consumption.
This kind of problems can be caused by:- Wrong cable termination. Too many or too few termination resitors. Must be exactly 2 one on each end of main bus. Each stup length should not exceed 6 m.- False or broken tranceiver. - Program filling the bus. If you e.g. have loop sending data to the bus, but you logic fails and it will send data on every loop, bus will come to nearly 100 % load.
What hw you use? Do you have alternate device to test?