Proper Way to disconnect battery to not Brick FRM ?

Mic10is · 05-26-2022, 02:42 PM

IS there any "proven" method for safely disconnecting/reconnecting battery without bricking the FRM?

I find it quite annoying that something as basic as disconnecting negative battery terminal to safely work on vehicle electronics or even swap out seats, can cause a key vehicle module to stop functioning.

I currently have my FRM sent out to be reflashed.

Ill obviously need to reinstall the FRM as well, whats the best way disconnect/reconnect module so it doesnt brick upon reinstallation?

bender128 · 06-21-2022, 09:12 PM

I've never seen an FRM get bricked from disconnecting a battery and I was a BMW tech for a few years. The FRM typically gets bricked when your voltage is low and/or you have a voltage spike.

The 1 thing we always did with eXX chassis cars was to always keep a battery charger attached if ignition was on, otherwise either ignition off or engine on.

05-26-2022, 02:42 PM	#1
Mic10is New Member 3 Rep 7 Posts Drives: 128i Join Date: Apr 2022 Location: Holly Springs, NC iTrader: (0)	Proper Way to disconnect battery to not Brick FRM ? IS there any "proven" method for safely disconnecting/reconnecting battery without bricking the FRM? I find it quite annoying that something as basic as disconnecting negative battery terminal to safely work on vehicle electronics or even swap out seats, can cause a key vehicle module to stop functioning. I currently have my FRM sent out to be reflashed. Ill obviously need to reinstall the FRM as well, whats the best way disconnect/reconnect module so it doesnt brick upon reinstallation?
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06-21-2022, 09:12 PM	#2
bender128 Second Lieutenant 89 Rep 232 Posts Drives: BMW 128i Coupe Join Date: Sep 2020 Location: Toronto, Canada iTrader: (0) Garage List 2015 BMW M3 [0.00]	I've never seen an FRM get bricked from disconnecting a battery and I was a BMW tech for a few years. The FRM typically gets bricked when your voltage is low and/or you have a voltage spike. The 1 thing we always did with eXX chassis cars was to always keep a battery charger attached if ignition was on, otherwise either ignition off or engine on.
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