ECU reset after dead battery??

ceej269 · 12-26-2021, 08:07 AM

I have a 2011 128i and the battery went dead. It's a new car for me so I'm learning the ends and outs. To charge my phone I had to hit the button for accessory power which apparently drained my battery.

After a jump I am now in limp mode only after having the car 3 days. I read that you can hold the trip button until you see reset but that never happened. I'm going to attempt disconnecting the battery today. Will this work?? Is resetting the ECU what I must do to get out of limp mode after a dead battery? Is resetting it going to affect my car's performance?

My neighbor tried connecting to his (old) equipment to reset but would not work…can I limp to Autozone and have them do it?

It's very disheartening to finally get my dream car and on day 3 it's no longer drivable. And with the down payment and high monthly payments, I can't simply take it to a shop or dealership and shell out $$ that I don't have for something so dumb as a dead battery. (The car starts fine now…it's just in limp mode)

I'm fearful of what other problems are in store for me

*Update* I did the battery disconnect and discharge. Waited 10 minutes. Nothing changed.

2008e92328i · 12-29-2021, 05:02 PM

Sorry to hear that! I really don't know anything about the battery or how it works, however, if you're in limp mode, I believe you should have a CEL. Pull the codes and see. Or call your local or nearest BMW dealer to see if you f they can assist. Again, sucks you have to go through this. You'll figure it out though! Good luck

12-26-2021, 08:07 AM	#1
ceej269 Registered 0 Rep 2 Posts Drives: 2011 BMW 128i (automatic) Join Date: Dec 2021 Location: College Station, Tx iTrader: (0)	I have a 2011 128i and the battery went dead. It's a new car for me so I'm learning the ends and outs. To charge my phone I had to hit the button for accessory power which apparently drained my battery. After a jump I am now in limp mode only after having the car 3 days. I read that you can hold the trip button until you see reset but that never happened. I'm going to attempt disconnecting the battery today. Will this work?? Is resetting the ECU what I must do to get out of limp mode after a dead battery? Is resetting it going to affect my car's performance? My neighbor tried connecting to his (old) equipment to reset but would not work…can I limp to Autozone and have them do it? It's very disheartening to finally get my dream car and on day 3 it's no longer drivable. And with the down payment and high monthly payments, I can't simply take it to a shop or dealership and shell out $$ that I don't have for something so dumb as a dead battery. (The car starts fine now…it's just in limp mode) I'm fearful of what other problems are in store for me Update I did the battery disconnect and discharge. Waited 10 minutes. Nothing changed.
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12-29-2021, 05:02 PM	#2
2008e92328i Private First Class 44 Rep 102 Posts Drives: 2008 328i coupe Join Date: Apr 2017 Location: Hoover iTrader: (0)	Sorry to hear that! I really don't know anything about the battery or how it works, however, if you're in limp mode, I believe you should have a CEL. Pull the codes and see. Or call your local or nearest BMW dealer to see if you f they can assist. Again, sucks you have to go through this. You'll figure it out though! Good luck
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