I don't know where the disconnect is here, but let me take it one issue at a time I guess, and ask that you accept this as constructive with the goal of ensuring accuracy in interpretations and conclusions regarding "transaxle efficiency" and have some faith that I have reasonably in-depth understanding and experience in these things in general. Being open to constructive criticism can only strengthen your position.
Lets address the lack of mg1 sensors a second (hopefully you already understand some of the concerns in converting current to a real torque value, which is what the ECU seems like it is doing).
A few sites seem to infer mg1 parameters from mg2, i.e. in
Request help on decodes for MG1 / MG2 rpm - PriusChat Forums
Quote:
* MG2 rpm =~road speed in mph x 57
* MG1 rpm =(3.6 x engine rpm) -(2.6 x MG2 rpm)
|
There is nothing unusual in automobile ECUs about inferring what is going on based on indirect readings, my saturn is a prime example where they saved a few cents by programming the gear ratios into the transmission instead of adding a clutch switch, or were able to eliminate the cam position sensor entirely by looking at other parameters. It happens all the time, the prius, or "aftermarket" tools are no exception.
But in regards to your stated goals, "measuring transaxle efficiency", where this figure will be publicly available, I need to point something out.
So if, like I was questioning in the other thread, we try to "measure" the efficiency of the circuit between MG1 and MG2 when the battery is inactive, and the MG1 parameters are derived from MG2 in the ECU black box (and not really guaranteed accurate without further research), then we are not necessarily looking at a real measure of MG1->MG2 efficiency, we are simply reverse engineering the MG1 power reporting code.
Can you let me know if that much make sense?