Difference between HPT SD patches and tricking MAF to fail?

[vwnut8392]

As the subject asks, does anyone here know the difference between if any when you apply a speed density patch with HPtuners vs just changing the several suggested variables in the mapping to force the MAP sensor to fail and revert to speed density?

[AngelMarc]

A DTC being read by scanners is all I'm aware. I've had a 12587603 P59 behave as if it's speed density without the DTCs and MAF disconnected, but I didn't get open throttle spark tables.
Even with the TPS and VSS setting for that set to 0. It just wouldn't.

[hjtrbo]

As reported on the hp forum, the sd patch fixes a glitch where the reported airmass momentarily drops to 0 and all fuelling is lost. However, HP did not release the SD patch for all OS's. For those that remain, the bug is with the spark^2 terms in the ve co-eff calcs as was proven by hp forum member verlon. The solution is to 0 out the spark^2 ve terms.

[AngelMarc]

link?