Keeping misfire diagnostics enabled with MAF failed

[aaronc7]

Has anyone been able to figure out if it's possible to keep misfire diagnostics/detection active when the MAF is failed, aka running speed density? I know there's a slew of conditions that need to be met in order for misfire diag to operate and MAF is one of them. I figure there has to be somewhere in the logic that defines this and a workaround for it.

I'm pretty new to all this PCM hacking stuff, but I have been sifting through the info posted on github by NSFW and poking around and trying to learn Ghidra etc. But I'm still probably in over my head at this point.

I did find something interesting (maybe) in the calibration section:

0x1889A, "DI_MISFIRE_KE_MISF_INHIBITING_FAULTS ", If TRUE is specified for the indexed fault group, then any active fault within that group will inhibit the Misfire diagnostic.

I tried to do down this rabbit hole a bit more, what are these 'indexed fault groups", is the MAF test part of one of them, can I change that value to FALSE perhaps? I tried my best to follow the logic with this, but came up empty handed.

Then again, maybe there's a reason that this is difficult to accomplish and that's why HPT and EFILive don't include it in their custom OSs.

[aaronc7]

Well I played around with all 32 bits or "indexed fault groups" and in all cases misfire detection was still disabled with the MAF failed.

So looks like I am back to square one and currently out of ideas. May revisit it later if I come across anything.

[VX L67 Getrag]

Dont you have to enable the maf to work & just disable the SES light so it still runs that routine?

[aaronc7]

I'm not exactly sure what you mean. My car still physically has a MAF (I use the IAT). I set the high frequency fail limit to some really low value so it 'fails' right away and reverts to VE only. I don't have the MAF DTCs disabled because it needs to see the MAF fault in order to revert to VE.

I can just flash a tune with the MAF re-enabled do see misfire results, but I was looking for a way to have it working without a MAF tune being required.