Is there a need to go back to a stock tune for a battery replacement?  My assumption would be that I don't have to but no harm in asking I guess. My battery showed me a slower than usual crank after the car sat unused for 2 days. I figure I won't get another nice unpainful warning so I will take it in to my dealership and have a new heavy duty installed first thing in the AM.

You wouldn't normally return to the stock file, just for a mere battery replacement, however, since you stipulate your intent on bringing the car to the dealer to do so, you should consider it, just to be safe.

Why? Because IIRC, Dealer Service Dept.'s routinely check/perform other updates to the ECM as a matter of routine practice.

So better to be safe, than sorry.

Sent from my DROID RAZR HD using Tapatalk

Should be fine, unless you're afraid they'll scan for the tune and act on it as far as your warranty or wreck your tune with an update.... They can tell even if you go to stock by counting the number of flashes and comparing it against service records. 

You can probably do better on battery prices with free install if you do it yourself.

The advantage to having it dealer installed is the free towing offer.  However, if your insurance covers towing, you are all set.

I would never go to the dealer with out returning to stock.  Like BPD said, they may update your ECU without telling you.  Then, your screwed.

Thanks all. My dealer knows I'm running a tune so I can tell them not to flash an update. For some reason I was worried that the battery disconnect might cause a problem but my instinct was that it would retain whatever tune was loaded when the battery was disconnected. Sounds like that's what everybody is telling me. I went in a month ago to have this battery replaced and they tested it and told me it was fine for now, and to hold off the replacement. Reluctantly I followed the advice, but I've been watching real close.  Now I have the age, the light on top going red, and now my last warning a noticeably slower crank from usual. No more waiting....new battery tomorrow morning!

YAY!

You could put one of these in the OBD2 port for future worries at a dealer who knows you have a tune.

Cool. Never saw one of those. I always have my Bluetooth sending unit parked in the OBD outlet. Might give a thoughtful person/technician pause. Never a guarantee though. lol

I was poking through Forscan and there is a battery replacement recalibration to run when the battery is replaced (at least on my 13).  There are current clamps on the battery cables but I have no idea what kind of logging is being done that the car would next to know when a new battery is installed.

Without using an "ecu saver" you'll probably lose the learned values like fuel trim, shifting, and idle control along with other stuff I'm sure I'm forgetting.  But if you're flashing back to stock that would go away anyway.

My experience with other tuning solutions is, if the battery voltage is too low, you cannot write back (flash) to the ECU.

That doesn't sound very good.

Quote from: dcpatters on December 24, 2013, 01:43:06 AM
My experience with other tuning solutions is, if the battery voltage is too low, you cannot write back (flash) to the ECU.

Standard practice to prevent corruption of the ECU.  You see similar warnings when updating Windows or BiOS about the computer being powered and untouched during the process.

Quote from: BiGMaC on December 23, 2013, 10:51:24 PM
You could put one of these in the OBD2 port for future worries at a dealer who knows you have a tune.

That's cool, where did you pick that up? Won't mind having one, even though my dealer is aware of the tune and I always remind them not to flash without warning me so I can put the stock settings back in, but so far I haven't had to return mine to stock.

 mj.....

There's one on eBay: http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1313.TR0.TRC0.Xdo+not+flash+obd2&_nkw=do+not+flash+obd2&_sacat=0&_from=R40

or Amazon (cheaper):
http://www.amazon.com/Daystar-KU71124BK-Flash-OBDII-Plug/dp/B00ASKRKQY

or Daystar (cheapest and available in black or red... . It does a one click online price match)
http://www.jegs.com/p/Daystar/Daystar-Do-Not-Flash-OBDII-Plugs/2860350/10002/-1

or just Google "do not flash obd2" or go to Daystar and search for an auto supply in your area bu zip code that carries them