Hacking/tuning the jeep ecm

[shelgame]

You probably do not make enough to pay someone to do this work. It takes a lot of time.


Math. Mopar systems used math equations instead of lookup tables in some areas. You would need to edit the equation instead of tables full of data.

I think he meant the 2D tables. Chrysler used a unique format for the 2D lookup tables. Instead of just putting in X,Y coordinates and using straight interpolation (which must calculate the slope to complete the interpolation); they actually simply encoded the pre-calculated slope into the table. Takes up twice as much storage, but probably only a tenth of the computation time. They started using that format back in '84 in the very first ECU which used a 6805(?) processor that had no divide instruction built in. So, the interpolation would have tken even longer to complete. It was just much easier to give up a little data space to save that precious computation time. Pretty ingenious if you ask me. Since it was a unique format to Chrysler, they kept it even when they went to the more powerfull 6811 (which actually can do division pretty easily).

Because they encoded the slope, TunerPro cannot fully recalculate the 2D tables when a point is moved. TunerPro isn't setup to do the slope. The only programs that do it are D-Cal, CHeM, and the newer MP Tuner.

For what it's worth, I have completely dis-assembled the turbo code back to my own source code that can compile a brand spakin' new binary.