GTJim

Had my car tuned this past summer. When I put the car up for winter storage I disconnected the battery instead of hooking it up to a battery tender. Prob should have thought about this before but now I'm wondering with the battery being disconnected so long will the ECU retain the tune or will it be lost due to it not being connected to power.

I can probably contact the tuner and get it loaded again but I'm hoping I can avoid that hassle.

CalF

It will be fine.Only way you lose or corrupt data is if the ECU has a failure itself.Think of it like powering down a home computer and unplugging from the wall socket.Fire it up months later and your data is still there.

QCVette

Disconnecting the battery will not lose the tune. It is programmed into the computer and should not go away unless another tune is written to the computer.

However, I think the long term fuel trims are learned values. They are the fine adjustments to the basic tune values. These fuel trims will be lost. However, they will be relearned by driving the car a few miles.

In short, you should be fine. The car will be back to normal after you drive it a while.

GTJim

Thanks guys! Next time I'll put the battery tender on it.