[CJW1974]

Hi all, I am a complete newbie when it comes to coding and electrically "complex" cars. I have a 2011 335d with 60,500 miles on it. Bought it with 32,000 miles and it is 100% original (including the battery). No check engine lights or SES lights to date until today when it had its first slow crank and the "Increased Battery Discharge" warning came up. So my question is, what is the safest way to replace the battery to minimize the risk of bricking any of the computers in the car? As well, my mechanic can code for the battery but I would like to learn the basics and getting the tools to code for the battery seems like a good place to start so any advice on that would be great. Thank you!

[ctuna]

No battery back up it will blow fuses.
And not back up anything worth backing up.
The only thing you loose that is visible is the date and time.
If you have x drive you will get and x drive error on power up this
will disappear if you drive the car a little or you can turn the steering
wheel to both stops.
If you have an automatic transmission the car may shift a little differently
as it reestablishes the shift adaptions.
The battery distribution block is awkward to deal with mark any wires you
have to remove to get that battery out.
If you have trouble registering the battery make sure the bsd cable wasn't
pulled out when you where messing with the battery wiring.

If you want complete diagnositics Inpa and Ista D
If you are not technical and don't want to be bimmergeeks pro tool.

There are many DIY's on ytube and here.
Read the battery thread there are many.
If you match the battery size and type you only need registration.
If you change the battery size and type you need programming.

https://www.e90post.com/forums/searc...rchid=68409771

[CJW1974]

Originally Posted by ctuna

No battery back up it will blow fuses.
And not back up anything worth backing up.
The only thing you loose that is visible is the date and time.
If you have x drive you will get and x drive error on power up this
will disappear if you drive the car a little or you can turn the steering
wheel to both stops.
If you have an automatic transmission the car may shift a little differently
as it reestablishes the shift adaptions.
The battery distribution block is awkward to deal with mark any wires you
have to remove to get that battery out.
If you have trouble registering the battery make sure the bsd cable wasn't
pulled out when you where messing with the battery wiring.

If you want complete diagnositics Inpa and Ista D
If you are not technical and don't want to be bimmergeeks pro tool.

There are many DIY's on ytube and here.
Read the battery thread there are many.
If you match the battery size and type you only need registration.
If you change the battery size and type you need programming.

https://www.e90post.com/forums/searc...rchid=68409771

I have ordered a K+DCAN cable to use with my laptop since I am an iPhone user. I am genuinely interested in coding and intend to learn how to use Inpa and Ista and I found a thread explaining how to get started. I plan to keep the car for a long time as my road trip car since I pack light and the fuel economy and power is great. I just did not know if there were any tricks to make the battery change easier on any of the modules so I thought I would ask. Thank you!

[ctuna]

You will need a way to Run windows on your apple devices I guess it's
Bootcamp or some program like that.

[CJW1974]

Originally Posted by ctuna

You will need a way to Run windows on your apple devices I guess it's
Bootcamp or some program like that.

I should have specified, my laptop is windows, just my phone is apple. I may get an android device at some point just to watch numbers in real time as I drive but for now I will just use my windows 10 laptop.

[sdbmwcoding]

The only thing you risk bricking when changing the battery on an lci coupe/sedan is your frm3 module. Faulty frm3 units will not boot up after a complete module reboot which replacing battery would do. Keep in mind not all cars with frm3 modules will have them fail, but they are definitely more prone to failureZ There's no way around this though. If it does fail it's under a 10 year 150,000 mile warranty. As long as you're getting the same spec battery you only need to register it to the car. Coding a battery is only required when changing amp hour ratings or switching to an agm if you're currently running non agm.

[CJW1974]

Originally Posted by sd*********

The only thing you risk bricking when changing the battery on an lci coupe/sedan is your frm3 module. Faulty frm3 units will not boot up after a complete module reboot which replacing battery would do. Keep in mind not all cars with frm3 modules will have them fail, but they are definitely more prone to failureZ There's no way around this though. If it does fail it's under a 10 year 150,000 mile warranty. As long as you're getting the same spec battery you only need to register it to the car. Coding a battery is only required when changing amp hour ratings or switching to an agm if you're currently running non agm.

I have a flooded battery and I was going to switch to an AGM so I will need to code it. I guess this is a good time since if the frm3 bricks then I will be just in the nick of time for warranty. I do stay away from dealerships as much as possible especially my local dealership (which is an hour and a half away) because they havent been very helpful in the past. Ironically they screwed themselves out of a sale of a car by not being helpful. I went there first to buy a car and they gave me a serious run around, assuming it was because I was 19 at the time, and so I strolled over to the next door neighbor which was a Ford dealer and they happened to have this cherry of a car sitting in their back lot that just came in from a one owner and I immediately made a deal on it and drove it straight to the BMW dealer to get some things for it and you should have seen the salesman's jaw hit the floor when I stepped out of it. Anyway, after going way off topic, thank you for your advice!