[S1000RR]

Still trying to fix my Xenon headlights problem and someone suggested
I pull the negative side of the battery for a bit to "restart" the system.

I just got the battery replaced at the dealership a week ago and they had to reprogram the battery.

If I pull the negative side for 10 minutes, will I need to get the system reprogrammed?

I have a 06 E90 Sport with Navi and premium if that factors into the equation at all.

Thanks again!

Also, if anyone knows if there are any other fuses for the headlights other then the ones in the glove box
I would appreciate that as well.

[SpaceGrayE90]

I wouldn't unplug your sh!t if you don't know what you're doing

[johnbuz]

"I wouldn't unplug your sh!t if you don't know what you're doing"

Thats about the most useless reply yet. Great way to help.

[S1000RR]

Originally Posted by johnbuz

"I wouldn't unplug your sh!t if you don't know what you're doing"

Thats about the most useless reply yet. Great way to help.

Indeed. Thought that I was in the Honda forums for a second.

[campbelly]

Originally Posted by S1000RR

Still trying to fix my Xenon headlights problem and someone suggested
I pull the negative side of the battery for a bit to "restart" the system.

I just got the battery replaced at the dealership a week ago and they had to reprogram the battery.

If I pull the negative side for 10 minutes, will I need to get the system reprogrammed?

I have a 06 E90 Sport with Navi and premium if that factors into the equation at all.

Thanks again!

Also, if anyone knows if there are any other fuses for the headlights other then the ones in the glove box
I would appreciate that as well.

Originally Posted by SpaceGrayE90

I wouldn't unplug your sh!t if you don't know what you're doing

to actually be helpful and not a dick /\
he does have a point but did not have to put it like that at all, what he was trying to say is if you dont know what you are doing, then you should take a bit of time and research (like he did) how to do what you wanna do. This forum is very helpful for picture by picture DIY's.

to answer your question finally,
yes, its perfectly fine to disconnect your battery for 10 min...i have done it for much longer than that when im changing out my steering wheel etc...

JUST MAKE SURE you DO NOT close the trunk while the battery is disconnected or you will not be able to open it to reconnect the battery and your basically screwed...

some people also say to put in your key and put your headlights to the ON position right before you reconnect the batter to not direct all of the power right to the computer and potentially fry it (may be a myth, but no harm in doing it)

hope that helps

[onebadmofo]

Originally Posted by campbelly

JUST MAKE SURE you DO NOT close the trunk while the battery is disconnected or you will not be able to open it to reconnect the battery and your basically screwed...

You can use the key to open the trunk.

[s1neater]

Nothing will need to be reprogrammed, Just disconnected mine to install the OEM alarm and the only thing (at least on mine) that will pop up once you reconnect it is the computer saying active steering is disabled if you have it as an option. All you have to do is go for a quick spin and this should be corrected. (Although I do have to take it to the dealer to get it programed for the alarm since it wasn't programed for it originally.)

[lito]

No need. I disconnected mine when I installed new BMW Perf steering wheel

[mike-y]

Originally Posted by onebadmofo

You can use the key to open the trunk.

I believe the newer cars no longer come with the keyhole in the trunk, so he is right if it's a newer E9x.

[bumere90]

no u don't have to reprogram it.

[RBinDC]

Originally Posted by mike-y

I believe the newer cars no longer come with the keyhole in the trunk, so he is right if it's a newer E9x.

You believe right! I can't believe BMW eliminated the key access.

Suppose your battery goes dead. The remote system won't open the trunk with no power available. However, there are several ways around this.

1. Open the hood and get someone to jump start the car. Presto, you have power.

2. Plug a 12v battery (like the one in smoke detectors) into the remote power outlets using a device you can buy at AutoZone, etc. The battery should have enough power to open the trunk once.

3. If you have the ski passthrough in your back seat you can open that and with a clothes hanger hook the emergency trunk lid release and open it manually. Note: you can't fold the back seats down for easy access to the trunk because the release controls are (you guessed right) - in the trunk!

[335i 07]

Yes, register your battery to be safe with a BT tool. You can burn your charging system in your car if you don't. The reason the battery needs to be registered is to tell the alternator when to charge your battery. The system isn't designed to run all the time so the car needs to know the starting voltage and capacity. Correct me if I'm wrong.

[Slamaster1261]

Originally Posted by johnbuz

"I wouldn't unplug your sh!t if you don't know what you're doing"

Thats about the most useless reply yet. Great way to help.

hahahahahahahaahahahahahaha dude this had me rolling for a long while.

[speedfan]

I've unplugged the battery twice & accidently closed the trunk twice on those 2 events.
It sucks that BMW doesn't make a manual latch to open the trunk (like for the hood).

I had to use another car's battery to ground it to open the trunk.

Anyways, to OP, no, you dont need to reprogram anything other than correcting your clock. The date is still saved correctly.

[RBinDC]

Originally Posted by speedfan

I've unplugged the battery twice & accidently closed the trunk twice on those 2 events.
It sucks that BMW doesn't make a manual latch to open the trunk (like for the hood).

I had to use another car's battery to ground it to open the trunk.

Anyways, to OP, no, you dont need to reprogram anything other than correcting your clock. The date is still saved correctly.

I think BMW eliminate a manual latch to prevent someone who breaks into the car from getting at stuff locked in the trunk. There is a manual emergency release in the trunk but it is not easy to get to and a thief would likely not want to fool around trying to fish for it with a coat hanger.

[listerone]

Originally Posted by RBinDC

You believe right! I can't believe BMW eliminated the key access.

My '09 "d" had a key slot for the trunk...it's kind of hidden up above the plate.Other years/models may vary,of course.

[RBinDC]

Originally Posted by listerone

My '09 "d" had a key slot for the trunk...it's kind of hidden up above the plate.Other years/models may vary,of course.

I looked at my car (2011 335is) after this thread was started. Sure enough, no key hole. They must have eliminated it on the 2010 or 2011 models.

[DIABLOW]

I have disconnected the battery of my e90 325 sport LCI for nearly 5 months with no problem and no need to reprogram anything. Don't listen to your mechanic trying to con you by saying you have to reprogram your car. He is just trying to make easy money from you. Warning!! never disconnect your red battery terminal only the black one. If you do disconnect the red one by mistake the battery can only be accessed from the boot and the boot will not open without the power. It might have to be disassembled with great difficulty.

[tosaytheleased]

Will doing this reset the computer?

I want to reset it after installing all of these new parts.

[sandiegobmw1]

Originally Posted by S1000RR

Still trying to fix my Xenon headlights problem and someone suggested
I pull the negative side of the battery for a bit to "restart" the system.

I just got the battery replaced at the dealership a week ago and they had to reprogram the battery.

If I pull the negative side for 10 minutes, will I need to get the system reprogrammed?

I have a 06 E90 Sport with Navi and premium if that factors into the equation at all.

Thanks again!

Also, if anyone knows if there are any other fuses for the headlights other then the ones in the glove box
I would appreciate that as well.

nope I've unplugged mine dozens of times. only thing you need to reprogram will be the time

[PhaseP]

On XDrive you may get an AWD warning also after battery disconnect, but turning the steering wheel side to sides all the way while parked removes this.

[lookalikehuuh]

not sure if i missed it on here but i didn't really see good instructions for OP to disconnect the battery since he doesn't seem to be the most techincal person ever.

Anyway... always wear eye protection. This is to protect your eyes in the event of sparks or anything else that can occur when working with electrical systems.

when you go to disconnect the battery ensure you are only disconnecting the negative(-) battery terminal. Do not disconnect the positive terminal.

Once the negative terminal is disconnected to not close the trunk. Turn the headlight switch to the "on" position to drain out any residual power you may have in the system. Wait a minute then place the switch back to the "off" position.

Once you have waiting your pre-determined time...5min, 10min, 20hrs, or however long. Carefully reconnect the negative terminal slowly. You may see small number of tiny sparks upon making contact with the battery. DO NOT PANIC this is normal.

tighten everything back down and your ready to go.


just an FYI the reason the dealership had to "reprogram" your battery is because when you replace an old battery with a new one the charge/discharge characteristics of the new battery will essentially never be the same. Theoretically reprogramming this battery to the car will extend the life of the charging system and battery. If you are just unplugging the battery for repairs/upgrades there is no need to reprogram anything.