SCT X4 Error: failed to download

[DoubleClutch]

Greetings all,
I'm currently experiencing some issues trying to swap tunes on my 14 gt with my X4. I drove the car about 20 miles to work this morning and stopped to get gas just before arriving. the car was tuned for e-85 but since I'm going to be driving it more I wanted to switch it backt o 93.
at the gas station I plugged in my tuner and tried to upload my 93 tune, the progress bar got to about 70ish percent, then some of the gauges and lights started flashing and it gave me and error saying that it failed and I must return to stock.
I hit return to stock and it did, but when I tried to upload the tune again it game the the error and the car wouldn't start. eventually it let me upload the stock tune again and I was able to limp the car to my office but now I'm stuck 20 miles from home with a stock tune but no cats and bigger injectors.
does anyone have experience with this? I'm at work right now and don't really have time to call SCT tech support.
one thing....the X4 device stays in the glove box of the car and hasn't updated for a while. could this have anything to do with it?

 

[96gt02]

Sounds very strange ive never heard of that issue but sct support is usually pretty good on the phone, better than limping home. Could always try to update it too, cant hurt but I dont see how that could be the issue

 

[DoubleClutch]

Sounds very strange ive never heard of that issue but sct support is usually pretty good on the phone, better than limping home. Could always try to update it too, cant hurt but I dont see how that could be the issue

I didn't think updating would be an issue either, I don't have the SCT device updater on my work computer either.
literally the one time I leave my daily driver home and take the mustang this happens....

 

[5lho]

Never do this. Don't retune a hot ECM and don't do it without extra voltage on hand, like a battery charger or another running vehicle and cables. Your tunes likely won't work from now on; you'll need to contact the tuner for help. You've likely freaked out the anti-theft system and you're VERY lucky you didn't brick the ECM. This is a common mistake people make. Next time do as I note, do it at home and have a 5 gallon can of your chosen fuel at hand and a nearly empty tank. This is what I do when I switch fuels.

 

[DoubleClutch]

Never do this. Don't retune a hot ECM and don't do it without extra voltage on hand, like a battery charger or another running vehicle and cables. Your tunes likely won't work from now on; you'll need to contact the tuner for help. You've likely freaked out the anti-theft system and you're VERY lucky you didn't brick the ECM. This is a common mistake people make. Next time do as I note, do it at home and have a 5 gallon can of your chosen fuel at hand and a nearly empty tank. This is what I do when I switch fuels.

so youre saying that trying to switch the tunes immediately after driving for a period of time is what caused my issues?

 

[DoubleClutch]

update: just walked out to the parking lot after letting the car sit for a while and tried to re-upload the tune and it worked this time. I started the car afterwards however, the first time it idled for a minute then with no throttle input the RPMS began to rise. turned the car off
Started it again and this time it idled fine, revved and returned to idle fine.
.... keeping my fingers crossed

 

[Gruca]

so youre saying that trying to switch the tunes immediately after driving for a period of time is what caused my issues?

Yes. I had it happen to me at the track before. I was making runs on my performance tune and wanted to switch to my drag tune. I parked after a run and the exact same thing happened to me. Once the car cooled down, I was able to return to stock (which is where mine got stuck) and upload my drag tune. When I first tried to upload the drag tune, it kept telling me there was a failure and I had to return to stock, but it wouldn't let me do my car wouldn't work at all. Once the car wasn't as hot, everything worked fine.

 

[autorres]

It’s caused by low voltage or that the equipment used to create the tune file is running a different firmware than the one on your handheld tuner. Keep your tuner updated. And when this happens to me I simply disconnect the battery stomp on the brakes several times and turn on the headlight switch to drain all capacitors in the electrical system then I connect the battery and the tune loads fine.


Sent from my iPhone using svtperformance.com

 

[me32]

Weak batteries are also known to do the things you described. Alway check your battery before tuning