Ok HPTuners - since our VCM controls are virtually non existant on our platform (not operationl), how can we reset LTFTs and knock learn.
Are they reset with a write entire reflash, or how about a write calibration only reflash? I have some gas milage testing I want to do, as well as figuring out in which cells its knocking (if any), and these are both easier to do with a clean slate
Unplug the battery ?
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BlackEco wrote:Unplug the battery ?
Does that work? Is there a good way to verify that it worked?
Does a reflash clear LTFT/Knocklearn data?
oldskool wrote:BlackEco wrote:Unplug the battery ?
Does that work? Is there a good way to verify that it worked?
Does a reflash clear LTFT/Knocklearn data?
I would think a reflash clears it, because it clears DTC's.
FU Tuning
If you go under the Engine Diagnostic button in the VCM scanner, there's an option to clear DTC's. I know it clears readiness states (I failed emissions because of it). I would think that would clear fuel trims.
As for knock learn...I dunno.
Ok put it this way. Suppose the ECM detects a knock in one of the cells of the HO spark table. It will interpolate between that value and the value in the LO table right? Supposidly, it "learns" the knock and does not advance to the full value in the HO table. So if you make a change (more fuel for example), and the knock is no longer there, will the ECM advance back to the value in the HO table, or does the knock learn need to be reset?
I can test the LTFT reset at some point, but there is no way to monitor "knock learn" is there?
It was my understanding that the ECU tries to get the HO fields, but only pulls to LO when knock is seen. I do not know this for a fact, but how I have understood it.
FU Tuning
thats not entirely true from what i gather.
from what i remember of my tune, when knock was seen the timing pulled out of it was the amount stated in the rate of attack for the knock sensor.
basically, you set the rate of attack (stock i think is like 6 or 8 degrees). when KR is seen, it pulls that amount of timing. i could be wrong and this may only be for when in PE tough...
as for resetting the fuel trims, generally, pulling both the positive and negative leads off the battery and shorting them together for 10 or 15 seconds will reset them, but i would think it would from a re-write too.
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