[1cleann55]

Hey guys. I have a 2011 335i with a ton of electrical faults. So far every component tied into the Bsd line has been swapped from the oil sensor to ibs to the water pump and alternator. Even the battery has been swapped. Only thing left would be the DME but I don’t feel like throwing a dme at the car just to not have it work. Also ever since these faults have been present the car misfires specifically only on bank 2 cylinder 5 and occasionally 4. I have new coils and plugs on all cylinders nothing works.

[weehe126]

That 3847 code is for the alternator. What did you replace it with? Did you code/register the new battery?

[1cleann55]

Originally Posted by weehe126

That 3847 code is for the alternator. What did you replace it with? Did you code/register the new battery?

Oem battery and yes battery coded

[weehe126]

I meant what did you replace the alternator with.

[1cleann55]

Originally Posted by weehe126

I meant what did you replace the alternator with.

Oem Bmw alternator

[weehe126]

No chance one of the connectors was installed wrong?

[DriveBikeRun]

I also have a 2011 335i with BSD codes, but without the misfires. My BSD codes are accompanied by over voltage codes on many other sensors. I can see the voltage spike in freeze frame data, so I'm trying to troubleshoot that now. My codes are triggered under heavy load (basically WOT) and hot conditions. As those conditions worsen, it progresses from merely setting the codes to a full on limp mode. In either case, a quick shutdown and restart brings everything back to normal operation.

If that resonates with you, check out the thread below. Many of us with 2011 335's have similar issues. I'm continuing to chase it, but would love for someone to figure this out!

Voltage drop to 11.9v randomly https://www.e90post.com/forums/showthread.php?t=1428829

[weehe126]

As crazy as it may sound, a buddy and myself have experienced high voltage spikes and the dash lighting up due to bad coils (assumed bad coils). We both swapped all of our coils, I have not had the issue since. He continued to have issues, bought the same coils I got and no longer had issues. Delphi GN1057

[DriveBikeRun]

Interesting. Were you getting misfire codes like the OP? I'm not getting misfire codes, but willing to try just about anything, lol. I did replace all coils and plugs with Delphi and NGK 95770 just before tuning back in May. Don't have the part number for the coils readily available.

[1cleann55]

Hey guys so I get fed up and lit the car on fire...

Lol nah but the car runs fine on a stock flash so I’m parting the car out. I’ve started seeing so many people get BSD faults on their N55s and fixes aren’t all the same. Some get fixed with new alternator and some need a DME.

[DriveBikeRun]

Dang, sorry to hear that you're giving up, but I understand. It doesn't keep me from using the car and there's so many things that I like about it otherwise, so I'm going to stick it out and keep plugging away at a fix.

So are you selling or just going back to stock? Best wishes with whatever you decide to do.

[DriveBikeRun]

Originally Posted by weehe126

As crazy as it may sound, a buddy and myself have experienced high voltage spikes and the dash lighting up due to bad coils (assumed bad coils). We both swapped all of our coils, I have not had the issue since. He continued to have issues, bought the same coils I got and no longer had issues. Delphi GN1057

So, coils ended up being my problem, too. I had new Delphi 10571 from RockAuto which are *supposed* to be the same as OEM, but apparently they weren't. They were either faulty, inferior quality, counterfeit or all three...don't know and don't care because now with genuine OEM coils, no more issues. Dealer traced the root cause of my voltage spikes on the ignition circuit to the coils. The spikes on the ignition circuit had damaged the alternator, which caused spikes on the charging circuit also, so new alternator needed as well.

OP, if you haven't parted out yet, I would give genuine OEM coils a try. I wasn't getting the misfire codes, but dealer said that's a different mode of failure (detected in the combustion chamber). The BSD codes are caused instead by backfeeding of voltage into the ignition circuit due to failed or insufficient insulation in the coil. You probably have both modes of failure going on, but it's the latter that they said causes the BSD codes.

[weehe126]

I would guess you got counterfeit ones. Get them from FCPeuro or ECS or the dealer and you should be good.

[houtan]

Thanks for figuring this out. I had a similar issue about a year ago. Here’s my thread: https://www.1addicts.com/forums/show....php?t=1419571

Never really figure out what was causing the issue. It kind of went away after reflashing my mhd map.

Went to a half mile race a month or so later and my car went crazy on the last run of the day. It was hot that day, more than 90 degrees. Here is the video:

After reading this thread and the other ther one linked here, you know what I realized? I had just installed new coil packs when all of this started, and they are Delphis!!!!

[GoodMoodley]

Houtan. thanks for sending me this link. DriveBikeRun thanks for all the info in this and the other thread with all the details of this issue.

Houtan is well aware of my issues. Quick recap. I have been getting the 18V issue, Wipers turning on etc... and going in to limp mode when running my car hard. Mostly happened at the track as I don't push too hard on the street. New alternator, new IBS and new battery. Problem never went away. Full bolt on, Pure Stage2 and recent custom MHD tune. Removed MHD and pushed a bit on the street and no issue. Errors came back when MHD was re-installed.

Houtan asked me if put new coils. I just checked my purchase history. I bought the Delphi GN10571 coils from RockAuto in July of last year and my issues popped up for the first time at my next track session after installing those coils.

Obviously I will be replacing those coils now. May even just pony up and get the Precision Raceworks setup.

http://www.precisionraceworks.com/in...&product_id=89

I hope that I don't have to replace my alternator again though. Maybe just the coils will do the trick.

Thanks again guys. These forums are golden.

[DriveBikeRun]

GoodMoodley, glad we could help! Sure sounds like the same issue. It was happening very often for me, but hopefully with yours being less frequent your alternator might be spared. Definitely keep us posted if you decide to go the PR coils route...even though my problem is solved, I still may go with the PR setup in the future. And now, thanks to being introduced to Houtan and reading his whole PS2 install thread, I'll probably be doing that, too 😜

[yayaya]

Originally Posted by 1cleann55

Hey guys. I have a 2011 335i with a ton of electrical faults. So far every component tied into the Bsd line has been swapped from the oil sensor to ibs to the water pump and alternator. Even the battery has been swapped. Only thing left would be the DME but I don’t feel like throwing a dme at the car just to not have it work. Also ever since these faults have been present the car misfires specifically only on bank 2 cylinder 5 and occasionally 4. I have new coils and plugs on all cylinders nothing works.

Dude had the same faults with my 11 335xi never solved the issues, gave up too. Took the car to two Bimmerpost recommended mechanics and a dealer and no one could figure it out. Multiple Plugs/coils/starters/batteries/ HPFP replacements since the car was purchased new and the issues always came back. DME checked out fine. I'm happy it's gone. Worst car I've owned.

I think the early n55s produced share too many fail components with the n54.

[GoodMoodley]

FYI. I just ordered the PR coil setup. Will be installing it over the winter with some other upgrades that I have been sitting on for a while. Won't be able to test it until the spring but will provide an update once I do.

[GoodMoodley]

Hey people.

Just an FYI. The PR kit is on sale this week.

http://www.precisionraceworks.com/in...&product_id=89

[AJL]

Originally Posted by GoodMoodley

Hey people.

Just an FYI. The PR kit is on sale this week.

http://www.precisionraceworks.com/in...&product_id=89

Son of a.... I just bought the kit like a week ago for full price

[Ozzie335i]

AJL, it cant hurt to ask them to honor the sale price. They can either credit you, or tell you to take a hike.

[GoodMoodley]

Here is a vid of a guy installing the PR coils on an N55. He reports the same over-voltage issues. Waiting to hear back from him to see if it solved the problem.