E92 M3 Alternator Replacement DIY Guide E90 E93 BMW M3 Repair Error Code 278D

Our E93 M3 alternator was starting to fail intermittently with BMW error code 278D and could have left us stranded in the middle of nowhere. This video shows how to diagnose and replace the alternator on an E92 or E90 M3 by removing the belts and radiator fan. The upper radiator hose broke unfortunately so I had to replace that and fill up the coolant at the end. Thanks for watching and please comment any questions down below.
IG: Cars_with_Ellie
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#e92m3 #bimmerlife #e90m3 #commissionsearned

[@Sals_Garage]

Starter replacement DIY video: kzbin.info/www/bejne/mnuweoeto6t9l7c

[@Alex-lx2pg]

Awww crap! That sucks on the coolant connector! Almost all done with the job too. 😔 The alternator is buried pretty deeply down there. Nice job on the removal and install. Nice job on the assistance too Ellie! As usual, love the detailed tutorial. Glad to see that you got your car back on the road again. Nice of Carl to provide the new hose! 👍 Would have been even better if you took your car over to Carl's Garage, and the labor was provided too! 😁

[@Sals_Garage]

Yea! So close to finishing, but I paid the price by not getting the coolant pipe ahead of time just in case it broke. Thankfully others can learn from my mistake 😆. Thanks again for the comment! Carl’s Garage sponsored this video luckily 😆

[@eliseypoo9]

Whooo! The process is harder than how Sal makes it look! Great video, hubby! 😍😍

[@Sals_Garage]

Thanks wifey for your help and filming the process.

[@reginald8405]

Very detailed, great Video Uncle Sal.

[@Sals_Garage]

Thanks Reginald! You have been supporting us from the very beginning. 🙏

[@Jethrumi]

Thank you sooooo much for the video. Helped me a ton with my e90 m3. The same nipple broke for me too. Had to buy a radiator hose from bmw the same day. which costed $150…

[@Sals_Garage]

Glad you found it helpful! Yea that hose is so annoying 😆

[@jonspec.]

Great video!!

[@Sals_Garage]

Thanks brotha!

[@connolly3000]

Brilliant, no forum anywhere actually stated this same code but some had similar issues. The issue I'm having is alongside the code 278D but I wasn't getting a signal from the IBS sensor or the Oil level sensor on my M3. Apparently they all use the same harness to connect up to the DME and upon following a similar issue regarding the DME, someone suggested in an old thread to remove the items one by one. Funnily enough when I remove the alternator plug I can read my engine oil level once more and I don't get a fault from that or the IBS sensor. My theory is that the alternator has pretty much packed up. When the car is idling I do get a voltage reading of 14.6-14.7v but the code still shows: 278D Alternator Missing.

[@Sals_Garage]

Thanks for sharing! Sounds like an alternator or voltage regulator issue. Good luck 👍

[@connolly3000]

Thanks Sal, I took the radiator hose off of mine to get the alternator out and kept it raised high after filling a jug. I can put back in what came out minus the few drops that got away of course :) Hopefully thanks to your video and experience, I won't break my top coolant hose flange. Managed to get the fan out with no issues, I hope it's just as smooth to get back in! Thanks Sal! @@Sals_Garage

[@Sals_Garage]

@@connolly3000 you got this! Fan should go back in smoothly but just watch out for that stubborn coolant hose. Good luck 👍

[@johnsomes396]

Great video.

[@Sals_Garage]

Thank you John

[@nutellacrazy4468]

Awesome helped alot!!!!

[@Sals_Garage]

Glad it was helpful! Good luck and thank you 🙏

[@JermsDNA]

Very important indeed. My cousin replaced it on his 72 Monte Carlo to be able to handle all his upgrades.

[@Sals_Garage]

That makes total sense, with all the upgrades the stock alternator wouldnt be able to keep up the charge.

[@Motorsports_3]

Hey man nice video and also you can bleed the cooling system by when the car is cold open the little plastic screw on the expansion tank and turn the car on. You'll hear the air bubbles start to escape from there and when u get a steady stream of coolant pouring out ur done just closes that screw turn the car off and check ur coolant level and repeat for how ever much coolant it needs.

[@Sals_Garage]

Thanks so much for sharing that information. I had a hard time finding out the proper coolant bleed procedure for this car. N55 was easy to figure out with the electronic water pump 😆

[@Motorsports_3]

@@Sals_Garage no problem man and yes I litterly spent hours trying to find how to bleed the cooling system on the m3 and the only info that pooped out was for the electric water pump in a n52 and n54 which got really annoying when the water pump is belt driven

[@Sals_Garage]

@@Motorsports_3 exactly 😆

[@qhkqchk2920]

i had alternator issue with my e92 and it got me stalled a good couple of times before got it figured out. at first i thought the battery was going out but the alternator was too. it kept triggering tons of error code and also a dct overheat code. the car was almost stranded in a single lane uphill traffic and that was definitely not fun trying to start the car again

[@Sals_Garage]

I can imagine that is quite a stressful situation. I luckily did not stall, but I noticed rough idle and the battery occasionally wouldn’t charge past 12 volts while driving from a cold start. Definitely glad we changed it in time.

[@JermsDNA]

I would have gone to prying to crying real quick HAHA😅

[@Sals_Garage]

LOL hilarious!

[@turdseyeview4763]

Sal, question: would a bad alternator make a whinning noise? I have one in my e93 and its driving me crazy! Some people say it may be power steering pump, or the pulleys...

[@Sals_Garage]

Sounds like power steering or pulleys. The alternator doesn’t make noise usually

[@Cawzzh]

hey my car stalled on me n some smoke came up n smelled like something was now shows codes 278D and 2B13 - speed detection could this be my harness fries or did my alt just die don’t know what could cause it to smoke

[@Sals_Garage]

I’m not sure but please let me know when you figure it out. Good luck 👍

[@TheWarewolf79]

Hi again Sal buddy... Just a quick question for you... Did you get the engine fault error on dash with reduced power when you had this issue? Did your car completely shut off? Many thanks for your response in advance 👍 cheers 🥂

[@Sals_Garage]

No shutoff or engine fault in the dash. It was a hidden code that only showed up on the scanner. I did monitor the charging my voltage and that is when I knew something was wrong when the voltage was only 12.6 with the vehicle running.

[@TheWarewolf79]

@@Sals_Garage Thanks for your prompt reply Sal...Well, my car went into limp mode earlier today, pulled the codes, and there were only two, 278D BSD Alternator missing (like yours), the other one was 5E19 DSC: Engine management interface...which is weird? Any ideas??

[@Sals_Garage]

@@TheWarewolf79 start with replacing the alternator. These cars are sensitive to low voltage issues.

[@TheWarewolf79]

@@Sals_Garage Thanks Sal...but I have just ordered the voltage regulator (main culprit), and will attempt to replace it from underneath car just like you suggested previously. What do you think?

[@Sals_Garage]

@@TheWarewolf79 voltage regulator will fix the issue but I wanted to replace the whole thing since I had a lot of miles on it.

[@shaythompsonn]

That Green tool - what is it ? Link please…. it seemed very helpful in this project

[@Sals_Garage]

amzn.to/3BQOXCh

[@shaythompsonn]

@@Sals_Garage 🙌

[@TheWarewolf79]

Nice video as always... I have same code 278D but alternator is charging fine around 14.2v and never dropping below 13.9v on heavy load/electronics... Battery is always full, car starts up fine every time, and finally, no dashboard faults. I just ran ISTA test as a regular checkup, and this was the only code present that didn't want to clear no matter what. I don't wanna change alternator if I don't have to, especially having a supercharger that shares its bracket with alternator bracket, which is a lot of work to get to... What do you think Sal buddy? 🤔 🙄

[@Sals_Garage]

Thank you for the comment. Unfortunately if you have the code the alternator will eventually start to fail slowly I had the code for months and eventually the alternator would stop charging on random cold starts and this only happened once every month or so but it’s still a risk. If the alternator stops charging I would just stop the car and start again and it would start charging again but I didn’t want to keep doing that so I changed it. Another solution is to just change the voltage regulator which would need to be done from underneath the car but does not involve removing the alternator. That will save you some labor and should fix the problem. Good luck 👍

[@TheWarewolf79]

@@Sals_Garage Thank you Sal for your nice explanation and help 👍 I could tell you're a kind good hearted person from your videos... Kudos to you for putting up with all your M3 issues... I'm a DIYer myself, but what gets me the most is the extended bending over while working on car...also my car is lowered which makes bending even worse. Engine is so far back closer to firewall makes me think the M3 is almost a front mid engine lol 😂 it's very close to it in design though hehe 😄... So ya, great idea 💡 I should attempt and replace the voltage regulator which is significantly cheaper, but most importantly, less labor-intensive where I could just replace it from underneath car without removing alternator! That's a great idea 💡 👍 thank you once again for your help, and keep up the good work... You deserve more subs and views and I'm sure you'll get there soon 👍 much appreciated 👍 Ken.

[@Sals_Garage]

@@TheWarewolf79 anytime Ken! Thanks for your kind words as well. You’re right about the back pain from working on this car. When I did the starter replacement, I felt it in the low back from bending over deep in to the V of the engine 😆. It does feel like a front mid engine design. The proximity of the engine to the firewall makes me dread the day I need to change the secondary air valves 😱 hopefully the engine stays reliable as it has been so far. Good luck again and let me know how it goes with changing the voltage regulator.

[@TheWarewolf79]

@@Sals_Garage hehe 😄 ya I saw your starter replacement video and I felt your pain lol 😂 I get a sore/stiff back for couple of days after working on car... BTW, when you say secondary air valves, did you mean secondary air/vacuum pump? If so, and if you're tuned for stage 2, normally those OTS tunes disable secondary pump due to no emissions requirements when you're decatted. Otherwise, I totally agree, hopefully you'll never have to do any more work on car, at least for a while as a nice breather... But we need to see more M3 contents though hehe 😄 😉 👍 take care and good luck 🤞 👍 cheers 🥂

[@Sals_Garage]

@@TheWarewolf79 the secondary air valves are in the very back of the engine almost touching the firewall while the secondary air pump is at the top of the engine. If either of them fail we won’t be able to pass smog in California. I swap back to stock every two years to pass emissions 😆. If the secondary air valves ever need to be replaced I might have to drop the transmission just to barely reach them 😮. More content for the M3 😆

[@shoryukensaucealtaccount7971]

👍🏻

[@Sals_Garage]

Thanks sauce 👍

[@donovananderson396]

Was it possible to remove the electrical wires before removing the alternator?

[@Sals_Garage]

You should be able to from the bottom.

[@donovananderson396]

@@Sals_Garage Ok thanks

[@Sals_Garage]

@@donovananderson396 anytime, good luck 👍

[@JermsDNA]

Aw dang the hose 😩

[@Sals_Garage]

Yes, that sucked lol. Kept us out of service for almost a week 😬

[@drago22alina22]

I have exactly the same problem as the guy in this video and code 278d intermittent, car idles low at idle 600rpm. Thinking to change the alternator kzbin.info/www/bejne/mGjbq2unnapqo8U

[@Sals_Garage]

Yes it’s the alternator for sure. Good luck 👍

[@drago22alina22]

Can i just change the pulleys and belts and not buy the whole kit? Don't need tensioners amd all of those, just pulleys, cant figure our what size they are, do you happen to know?

[@chopsmoke2280]

Wiggle and pry? More like wiggle and cry this shit not coming out🙃

[@Sals_Garage]

😆 try using some PB blaster and a larger pry bar. It will take time if it’s high mileage. Good luck 👍

[@chopsmoke2280]

@@Sals_Garage i got it out thanks

[@Sals_Garage]

@@chopsmoke2280 glad to hear.

[@chopsmoke2280]

@@Sals_Garage nobody told me getting it out was the easy part😭

[@Sals_Garage]

@@chopsmoke2280 getting it in is 😆