How to reset the LTFT

solo99 · Post by **solo99** » 07 Apr 2025, 01:35

Hi,

I had a leak on the intercooler hose and fixed this. After 500 miles, the LTFT is more stable but still at 12% - 15%. I did a smoke test again, but no leaks.

I was thinking the LTFT has to be reset, since the leak has been there for a long time. The LTFT does seems to be 'stuck'. I checked this article: viewtopic.php?t=21123

So I disconnected the battery for 3 hours, pushed brake paddel etc. to discharge any condensators, but it did not work. I had to relearn the windows and the display clock, but the LTFT has not been reset.
I disconnected the MAF sensor and restarted and removed the DTC codes, but no effect.

V70 - 2012 - 1.6 petrol DrivE ford engine with startstop. BTW, I did not disconnect the small support battery since is it so far away.

Should I remove the ECU fuse? Any possible negative side effects if I do this?
Is there no simple OBD app that can do this reset for me?

solo99 · Post by **solo99** » 11 Apr 2025, 01:59

I was afraid there would be no answers. It seems to be a very difficult thing just to reset the fuel mapping. At least, I think I searched the whole internet for it. Since I came across the topic on this website about how highly important it is to reset the LTFT after a fix, I gave it a go. But I understand this is not a common question many people have experience with.

Post by **abscate** » 11 Apr 2025, 04:27

The LTFT is set by integrating the STFT which resets when you disconnect the battery. If your reader doesn’t show Stft at 0 after a battery disconnect, it’s a reader fault

solo99 · Post by **solo99** » 11 Apr 2025, 11:37

Are you sure? I thought the LTFT is a based on the STFT values over a longer period. If I disconnect the battery and the LTFT is still the same after reconnecting, then I must assume it was not reset at all. If it was, the LTFT would start at 0 and if there is still a problem, it would climb back to it's previous values because the STFT would correct instantly and heavy.

solo99 · Post by **solo99** » 12 Apr 2025, 04:14

I pulled the ECM fuse (nr 36). At least I now know the LTFT is carved in stone

. Put the fuse back in after 20 min, no effect. Pulled the fuse again, 1 hour later in contact push brakes etc, wait for another 2 hours. Put the fuse back in, checked the LTFT, still the same. I give up, there is no way to reset it.