NefMoto

Hello all.

I am looking for some direction or guidance with regards to FUEDK. Is there an organized or strategic approach for tuning these maps properly? Is there a way to calculate the best values to populate these cells based on HFM measurements?

I can keep doing log after log while matching MSHFM to MSDK and adjusting numbers until the match closely at 100% DK. Then maybe limit DK with KFWDKSMX, measure, compare, tweak, etc.

Also, how does the axis data on WDKMSN get derived from MSNWDK? Is it the highest value in the corresponding throttle position, the average?

I've read this module several times and I must be missing something.

Long story short, I keep getting P1143 - Load Calculation Cross Check Upper Limit reached even though at 100% DK, HFM and MSDK are VERY close.

Any input would be incredible.

Thank you all in advance.

There is pretty much nothing to be "tuned" there.

what DFPM is 17551/P1143? have you traced it in the FR?

Should I revert those table back to stock and make adjustments in some other way? In theory, the throttle unit should flow the same no matter if air is being forced or sucked through it. So I can see where maybe these don't need to be touched since the throttle body is stock. Is it all going to be adjusted through WDKUGDN? How else might I go about getting HFM and MSDK to line up?

 I know you told me that tuning a supercharger wasn't going to be easy and you weren't wrong. The car is running pretty well otherwise, just trying to wrap my head around this fault the is coming up on occasion.


I have not. Not familiar with DFPM... I know this code is related to DEGFE though.

Why not find the root cause instead of guessing?

Looks like you only need to trace:

B_fkmsmx
B_fkpvmx
B_stend

CWDEGFE will disable it entirely (so you know if DEGFE is really the source of the DTC)


fkmsdksg_w > FKMSDKMX sets B_fkmsmx
fkpvdkg_w > FKPVDKMX sets B_fpkvmx

CWDEGFE in my binary is already set to 0... Maybe this is indicating that the issue isn't being created by DEGFE.

B_fkmsmx and B_fkpvmx are set right from the get go. The fault doesn't occur until the engine is in boost it seems.

Here's a log, in case anyone cares to take a look.

KFMSNWDK and KFWDKMSN describe the physical flow of the throttle body.
If the throttle is stock you should NEVER EVER touch these maps. It does not matter if the throttle is attached to an engine or a flow bench or whatever else, these maps will ALWAYS be the same, because they describe the physically maximum possible flow through the throttle at a given throttle opening.

Thank you for clearing that up. And that's what I had suspected.

And tuning a TB without flow data is a massive pita... Not worth the time IMO.