Pulling battery cable - what gets reset?

[06MonteSS]

after putting in a tune and/or modifying a tune and installing it, I usually fire up the car to make sure it still starts

then once that is done, I turn the key off and take it out, I disconnect the negative battery cable, step on the brake pedal a few times and turn the headlight switch on (to drain any residual power left in the system). I do this to reset any "learned" parameters by the ECM, such as fuel trims.

My question is, what else would get reset by doing this?

I've seen in another forum that someone said it would also reset timing/spark tables. so does that mean the the timing/spark settings I just installed with the tune are now gone and are back to stock/original settings?? Do I need to reload the tune again after reconnecting the battery cable??

Thanks!

[mikel]

I m not sure what is actually reset by doing this, but, there is no need to do this. We do not perform this operation on any vehicles that we tune here.

Thanks

[06MonteSS]

k... 'nother question then.. will it do anything or hurt anything to now just do a reinstall of the same tune again over itself?

although, I can't imagine that someone who's had their car tuned or even a general tune-up, and needed to replace a dead battery, would lose any part of the tune, which would inlude the timing/spark settings... so, I guess nevermind, I'm good to go...

Thanks man!

[mikel]

I like when you answer your own questions!

[06MonteSS]

just tryin' to save you some typing, I know how much you like to do that... LOL

[johan]

The only time i personally reset the learned values is if the fuel trims where waaaay off and the new tune should correct them or if you replace injectors with a different size.
There are also a lot of trans adaptive stuff that gets reset.

[06MonteSS]

cool, thanks - that's what I was wondering... cuz the last time I did it, the cable sparked when reconnecting, and the tranny didn't feel right - felt like it was being held back. Since I did this cable disconnect this time, everything seems a lot better. The very FIRST time I did the cable, it sparked/arced a couple times when reconnecting, and then my traction control and transmission lights were on in my dash, and the car would barely move no matter how far down I pushed the pedal... had to disconnect and reconnect the cable again to straighten that out.

Needless to say, I think after I just did it this time, I'll leave it connected from now on LOL

[upperme]

I think I might try this battery cable disconnect trick, as ever since I put the first tune in my car, the auto-up doesn't work on the driver's side window anymore. Auto-down still works though. I remembered having the window down when I did the first tune, but I never disconnected the battery for anything. More to come.

Jim

[06MonteSS]

while the tune "shouldn't" have effected the power windows or the BCM, ya never know what kind of anomolies can happen.

The thing I like about doing the disconnect to reset everything is, it will erase the "learned" driving habits and it seems to bring back some more pep.

When you go to reconnect the negative battery cable, put it back on the post quickly, to avoid a lot of sparks/arcing - that's what happened to me the very first time I tried it, and like I mentioned above it had set my TC and Tranny lights and my car would barely move. Disconnecting and reconnecting again fixed/reset that issue. And now the other times I've done this, I just put the cable on quickly to avoid the sparking/arcing and it's been fine.

Let us know how you make out and what'cha think.

[upperme]

OK, I was finally able to spend a little time with the mustang tonight, so I pulled the battery cable, went inside, made dinner and promptly forgot about it. So a few minutes ago, I went out and reconnected the cable, started the car and the window is now working normally. I am a happy muscle car owner once again... The Ford dealer would have probably tried to replace the entire drivetrain... LOL

Jim

[06MonteSS]

Cool!! glad to hear it worked!!

[upperme]

Me too!

Thanks alot for the tip... much appreciated!

Jim