I Fried My ECU :( This Can Happen To You As Well. | BMW N54 DIY

In this video I show you how to replace the transistors better known as MOSFETs on your ECU or DME. The early MSD80 equipped cars suffer a problem where the transistors that fire the injectors eventually fail.
From what I've been told this is due to the ignition coils pulling too much power from the circuit causing the injector transistors to fail. They eventually fixed this issue on the later 2008 and newer cars by introducing a newer ECU called the MSD81.
None the less you can fix this problem without needing to replace your entire ECU. The fix is to install stronger transistors which will not fail in the future. That is what I did in this video and I show you how to replace all your transistors.
You could do this as preventive maintenance or if you're getting a code for 30BA or 30BB. If you have that code your car will be running on just three cylinders so you can limp it off the road.
In rare instances it could be a failed injector but you could disconnect the injectors and try clearing the code, if it remains then you have a bad transistor. I also show you how to test for a failed transistor. If you're getting a 30AB or 30BB code then just order the transistors and replace them regardless.
Your can purchase the upgraded replacement transistors here (affiliate):
amzn.to/2ZhwrNe
You can purchase the hot air station I show in this video here (affiliate):
amzn.to/31KgQr1
You can purchase the solder flux here (affiliate):
amzn.to/2KJE1fz
Special thanks to Eurocharged of Houston and Spool Performance LLC for helping out with a spare transistor to keep my car running :)
If this is the first video you're catching of my consider subscribing, I upload regularly.
Thanks for watching! When you see the word "affiliate" listed beside any link in my description please know that this is a custom link and I will earn a small commission if you opt to purchase using said link. This is at no extra cost to you so it's a win all around :) Thank you!

[@NardoGreyRam]

Man!!!! You are really amazing A real DIY expert, from the biggest mechanical parts to the smallest electronics inside the ECU Really you are a big help to all the N54 community Thank you for everything 🤗👍👍👍

[@angelgaubeca6635]

Greetings from Panama City not US but on Latin america proud owner of a 335i N54B30 Powered.... Just made my night after replacing injector of cylinder 2 . I found this video and what a relief to know I have the MSD81 model ECU thanks a lot... there is no much knowledge down here on this cars particularly this rare E90 335i which actually is the 3rd one in this country AS far as I know that is running buttery smooth. Sincerely Gaubeca

[@BMWHOBO]

Just wanted to say thanks. I was driving home from work on day, went to do a pull, got a CEL, and my car was saying cylinder 1, 2, 3 misfire. I swapped the plugs and coils and got a code for injector 1, 2, 3 or possible DME internal error. Thanks to this video i was able to have my mosfets replaced (cylinder 2 was bad) for $145 and saved myself a diagnostics fee ($120) and the cost of possibly having to clone my DME ($300).

[@zk2532]

Bro! you smashed it with this one - even just the ref to the MSD80 vs MSD81 is enough to leave a comment - Nice one

[@papayspeanut]

I did a 3rd gear pull the other day in MHD stage 2+ and as soon as boost hit BAM! Misfires. Swapped coils and plugs and reset code and then I got the 30BA injectors 1,2,3 or DME internal fault code. Replaced all 6 of these mosfets and car is back to normal! Wanted to say thank you for posting this, I used the same ones you list here on amazon 10 for $10! Thanks again

[@Pe3Cee]

Good job mate, great helpful video as always! This happened to me 1 month before you, one of my mosfets also went south..I replaced all 6 which got the engine running smooth again but sadly my whole ECU needed replacing as I had further issues where my water pump kept running when ignition on without engine start. Water pump also ran for 5/10 seconds every 2mins when the car was off and locked and oil sensor became inactive. New ECU solved all matters in the end. MSD80 also, just a heads up for anyone who may end up unlucky like myself on this occasion.

[@motorcyklist9868]

You are probably the best KZbinr. I watch all your videos. Sooooooo much clear straight up learning!! Keep it upp FYI havent had any major issues but im ready for them

[@jesse550]

Great videos!! Thanks for the time you take to explain everything.

[@SaroG]

Nice video. For anyone doing this kind of job, make sure you use plenty of flux to prevent damage to the board!

[@blef7017]

First off, thanks for the videos, my 17 yr old son and I are learning a lot! He bought an '07 335i with 90k miles, nice little one owner car. Was leaking some oil so we did the valve cover and oil housing gaskets on it, was running great but then one night coming home from work he went into limp mode. I went to check it out and found one of the injector grounds was loose and arcing. We put it back on but no help, was still in limp mode with codes for misfire on bank 1. After paying $100 to have it diagnosed we were informed it was his DME. He didn't have $2k to fix it so we limped it back home and started looking online to see if there was anything we could do to fix it. We found your video and ordered the new mosfets and had a local shop solder them for us, but when we put it back in it was still in limp mode. We took the DME back out and found they didn't solder the chips to the board, only the two contacts. After we took it back and had them resolder the chips we put it back in and BINGO! Fired right up and was back to normal! Such a great feeling! He was hyped beyond belief! Thanks again and God bless brother!

[@scottxp800]

The ones that commonly fail are 1 and 5. Yours was #1 that failed, #5 is the one on the left of #1. Probably because they are next to each other in firing order they get the hottest and fail first. Firing order (as with most inline 6 engines) 1,5,3,6,2,4. Mine was #5 that failed. I replaced 5 myself with a soldering iron as a temporary repair. It looked terrible so I had a TV repair shop do all 6 when I could have the car down. 6 5 1 2 4 3

[@glasser2819]

yep, replace economy OEM Parts with better mosfets of higher grade equivalents: - higher max current spikes - lower minimal rds-on resistance This endure they dont heat up the PCB area so much. Bad ECU design without any form of heatsink.... imagine driving that car in Arizona summer: it can kill you 😂

[@Fix_It_Again_Tony]

You can also use solder paste, which is meant for hot air reflow soldering. It contains small particles of solder and flux in a syringe that you apply to the PCB. After removing the older FETs, I recommend using the solder wick and the iron to remove the older solder first, then apply some paste. You need just enough to cover the exposed PCB pads. Then place the part in the correct spot. You shouldn't need to apply too much downward pressure on the part. Once you've used the hot air gun to heat the board and the part, the solder liquefies and actually sucks the part down to the board due to the solder's surface tension. The part will usually self center on the pads when this happens. Use isopropyl alcohol to clean the board. Lysol just kills germs. I had this happen to my MSD80 as well and replaced the MOSFET with the same parts shown in the video. It's been working well for 2 years at 20psi in the midrange using the one step colder plugs gapped at 0.022". I am using the Delphi pencil coils.

[@nickolascain2994]

Nice job man... cool to have a nice indy shop located by you. Good to see the mosfets fixed your issue. Me and some friends have a small electronic repair buissness and do custom 3d printing etc. Might be making some customn n54 parts here soon. (:

[@twinturbo8304]

i have exact same car. done most of dyi bolt ons. love your videos i run jb4 and 91. catless dp and big inlets and IC and exhaust. keep it up!

[@jimg6264]

Happened to mine a few months ago, brought the new mosfets and my ECU to Jims TV repair in Longmont, CO and he did the soldering for me for free! Never met the guy before that day so if you're in Denver Area hit him up!

[@extra243]

I still own my 07 335i (180k miles). I Had 14 M3 and just traded in for 19 S4. For some reason I can not let the 335i go :) Your channel is awesome! Keep up the good work!

[@spankthemonkey3437]

Chau Nguyen you should have traded it for a supra, oh wait you did

[@cutkicker]

@@spankthemonkey3437 lol

[@jmunnadaboss]

You still have it ?

[@3dSick]

8 bucks for 10 transistors.. good God, you got me sweating when you said you were going to replace them all.. hands up to you man.. thanks for passing through the knowledge, I would buy this as prevention as I am running mhd stage 2, and only God know when would this happen.. Best..

[@devinramirez1581]

yo i know you commented a year ago but i have a question, i have stage 1 335i 2007, i pushed the rpms too high and the ecu failed and the first three cylinders are misfiring, will changing the transistors and coils do the job? it seems like u had the same problem as me

[@moisesromo3862]

God bless you bro 🙏 for helping out people 💯

[@adamsisneros8307]

for real man🙌

[@ethanjones774]

Dude your videos are amazing

[@anthonylockhart3654]

Wish I saw this video before I bought coils spark plugs and injectors 😂

[@n54mikey18]

Me to

[@brayden2912]

Meeee toooo

[@beeeef]

Yup same but you're future proofed now gents

[@krisgriffin9090]

Simply the best!

[@Markstevos]

Fantastic job mate.

[@peshaaa]

Great video, Amazing job!

[@staymedicatednyc]

Saved me so much money!! Thank you

[@SarmadAlraed]

Thank you for your time and help

[@maxnix346]

MSD81 has some logic enhancements also, does it not? Well presented with great detail.

[@JR-si6ef]

Turbos seem that they are doing good .. I'll be getting mine hopefully this week ..

[@taytaggementertainment7085]

😅 best video explaining exactly whats wrong with my car lol why is this video not first to pop up

[@rodgercravens5985]

You saved me so much money thanks for the video

[@MrNicoe36cabrio]

Thanks for the great tip. A lot of N54 guys will love it!!

[@andymitchell368]

She sounds good now 👍

[@benjaminlevi7792]

Good info thanks

[@orangexxxx3140]

I had this happen on my ms45.1 ecu on my M54. A bad ground on the coil pack harness took out the MOSFET on cylinder 1 creating dead cylinder.

[@cmcevill]

Bought you using your links, Thank you.

[@darth_art2101]

I did this to run precision coils as preventative measure. So far So good. Wonder how Lons it will last

[@Michael-rp5tc]

I was new to the 335i scene and installed Cobb on my 2007 E90. In less than 2 days, it blew my MOSFETS during a WOT pull. After a few weeks of research I figured it out and ordered MOSFETS from digikey for less than $5. I then took my ecu to a laptop repair store and had them replaced for $50. Popped the ecu back in and had a blown coil. Replaced that and I was good to go! Switched to MHD the next day. Car was totaled soon after from an elderly man pulling across my lane :(

[@ricardoo1641]

Michael damn

[@X11CHASE]

Series of Unfortunate Events

[@tru007jeffos]

thanks a lot man you the best please do not i repeat do not sell that e 90 we still have a lot to learn...

[@finnishmotorfreak7665]

how is the racing diffs progressive working? I heard they grip pretty hard

[@pinoysi06]

Your putting Bmw stealership our of business😂😂😂😂😂. 🔥 videos man👍🏽👍🏽

[@RobertoBlanco6425]

You are awesome 👍🏻

[@nikolaypavlov8398]

Hi I just watch the video (btw thumbs up for your job on the car and sharing it ). I've notice that you read your car with your phone. What is the name of the software that u use ? Thanks in advance

[@Toobs138]

Happened to me. I just upgraded to msd81. Thanks for the videos

[@AshByad]

Toobs138 if i have mhd map installed will i lose it if i upgrade to msd81 ??

[@Toobs138]

Ash Byad I don’t know when this happened to my car it was stock. I had a guy clone my msd80 to the msd81 I bought. I would think it would work but I don’t know for sure.

[@AshByad]

Toobs138 thanks for the reply man, appreciate it

[@maxnix346]

Smart move.

[@215Sugarfree]

I blew out 4, 5 and 6...Guy changed all 6 of them for me for $100 and works great..

[@sixspeedmaro]

I think we are in the same fb forums for n54's. In the group there a guy that thinks the PR coils dont cause an issue with the mosfet on the dme I told him that my tech told me that was the issue an he told me my tech didnt know what he was talking about

[@ntc490]

Mine blew too. PITA. Bought replacements from Digikey and used a hot air rig. Cost me about $10.

[@stefanbenz3395]

Thank you very much. With your help I fixed the MOSFET for cylinder 3 of my 2007 325i (European, only I guess) In Germany I bought 8 MOSFET N-CH 300V FDB14N30TM for 1.56€ each and replaced only the defect one. I'm not an electronic person and therefore trained a little with the hot-air device on an old electronic board before. My plan, in case a similar problem will return for one of the other 5 cylinders I will then change all MOSFETs. Do you think I should do it before? Thanks again. Very happy!

[@markokruc2993]

Have you ever considered upgrading the mosfets with modern SiHB30N60 mosfet which is much more robust and advanced than FDB14N30TM?

[@Jawdropping_Fart]

I'm really confused with this series of DME videos. If you upgraded the mosfets in MSD80, why was the very next video you trying to changing to MSD81? Did you blow the upgraded mosfets again?

[@genekelly8467]

You should wear a grounding strap-you can fry MOSFETS and gate arrays easily!

[@hackn3y199]

Fried mine the other day, I've had MHD on for a few thousand miles, luckily i was close to home. You can use kapton tape to protect smaller components from flying away, but I couldn't find mine and it went fine. So after the repair it was still running like shit, I got a code for #5 injector, and the 30bb code was gone. I replaced #5 coil and she's butter. So I don't know if one of the failures triggered the other...

[@wee_lifts_dough4798]

Is there a reason you went msd81? Did the install not work? I had code 30ba before having mine replaced. Now I have 2e32, 2e33, and 2e35 if you could let me know I’d really appreciate it. I watch all your content. A huge fan to say the least!

[@Willabeast]

fun fact this happened to a car i picked up for 2k best deal for a "blown motor" ive seen haha cost me 1.50$ it just has a steering light on lmk if u think you can help with that. (I was shocked when i figured out this was all thats wrong with it.) i can still drive it just fine but there is a steering light that is stuck on.. the steering seems like it wont turn as much as my other 335i tho so i havnt driven it much until i figure this issue out (please help with anything you can) also ur videos are great i love them

[@Willabeast]

also my nav says dsc disabled. i think it is due to the steering problem as well

[@mrtalky460]

Sir, I have 2 questions: 1: when I start my e46, the rpm goes to maximum, is it possible that my ecu is damaged? (any experience?) 2: can you just replace("plug and play") the ecu without any programing? thx in advance

[@cmcevill]

I can't thank you enough. I just try to buy using all your affiliate links

[@stevenshepard3819]

Time to go msd91 😎😎🤘

[@matthewverduft5774]

Bruh really your the best 👌 🎉😂

[@shaquandavis1884]

Hey hope you can see this comment but I have a 2007 335i thinking about going stage 2 I have the supporting mods but do you think my mosfets would go out with a tune ?

[@bmwi-do6rg]

I plan to solder my MOSFETs. Any tips on a beginner with a hot air gun?

[@truckerboymari3589]

need help asap... my car had the same code, i had my mosfet tested and they were good but i still was getting the code and bad misfire in cylinder 1,2,3, change injectors,coils and spark plugs. so i bought a ecu and the misfire went away. so km guessing the problem was ghe ecu. so i want to fix my ecu but i cant figure what the problem is if the tester saying the mosfet are good

[@LuisGonzalez-ph8zp]

Hi quick question does it matter the way you install the mosfets’ on to the ecu I’m removing mine right now and noticed some say N631AH others say N631AK? Note I have not received my new mosfets yet still waiting for em in the mail

[@1bad335ii]

Hey was wondering Was your car misfiring as soon as you start it ? Or after it warms up ?

[@jrod6902]

I have a 2011 335i and I’m getting the code 32E3 : EWS-DME Interface hardware fault. Could this possibly be a mosfet in my ECU? My car is stock.

[@rdrezi1717]

I just got the 30BA code on my 335i, the product in your link is no longer available is there another similar? That is close to the original price? I found one for 40 usd plus shipping but would like a cheaper option if there is one. Thanks

[@horaciok6269]

Will bad mofsets also cause the car not to start?

[@luiem1688]

can someone please help me. I have MSD81 with codes 30bb and 30ba. Any ideas of what this could be or who should I contact?

[@alejogom5]

How different is this ECU to the one on the F20 N13? Trying to find the right transistors, I’m getting the same error code on my 1 series

[@FrankBernal24]

I have this fault code along with p2c3c. Got some misfires on cylinders 4,5,6. Any guesses?

[@eddieedwards8267]

So mine is doing the same thing I took it to shop but mechanic said my wiring harness may be fried as well because cylinder 1 coil pack got too hot would you agree ?

[@MrFearless84]

Ok I was thinking it wouldn't start when I saw you burning those mosfets for so long. Next time just put the whole ECU in the oven on 100°C. Preheat and then work on it. It will be a lot easier and you will put much less heat stress on the elements.

[@richiee.2203]

Will a fried ecm cause drive train malfunction?

[@connorfaulkner3112]

I was working on my bmw engine and I got a shock from my coil pack and now my car won’t start crank or anything? No lights on dash you reckon I’ve fried my ecu also all fuses and relays are okay also my key wasn’t in ignition

[@Wolfpack-219]

Chasing down this 2C40 code after going ST... could this be the issue. DME needs fixing?

[@_bimmerboi8888]

Would this work if your DME isn’t catching the adaptation reset? Its confirmed its the DME

[@xTheGamerHeart]

i was hoping for the turbo video :'( nonetheless helpful video 👍

[@VehicularDIY]

Hopefully that acceleration clip gives you some idea, 14 PSI 95F and still pulled decent. They are awesome, soon you'll see clips accelerating at 25 psi.

[@xTheGamerHeart]

@@VehicularDIY i have been waiting for the dyno with the 25 PSI the moment you hinted that in the ignition kit video. can't wait for the video to decide

[@gregbanasik]

Vehicular DIY i just bought the Stage 3 from Shawn after your recommendation. No idea what to expect yet, let me know when you get dyno results and who your tuner is!

[@dfqnexxus3710]

Dude you are the best right now , I'm in Houston area how much you will charge me for this job since I don't have the tools for and I need my baby running, it's my dayli

[@annoyedby922]

your car is turning out pretty awesome man! I have a manual e92 and I have done a lot of the mods on your channel here. I have MMP Stage 3's but don't have upgraded coils yet. I have the MSD80 ECU so I guess I will be needing to address this at some point before upgrading coils. Are you going to be Dynoing soon?

[@Findingmatteo]

After mosfets are installed does it need to be te flashed or not

[@milehighboost5521]

Just as a heads up to anyone with an MSD80, i had just finished installing b58 coils with the b58 dwell and it immediately fried my already upgraded transister #6. I replaced all 6 about 2 years ago. Luckily i still held onto the other 4 from my 10 pack and quickly fixed it. Not sure if i can run a b58 dwell unless i upgrade to an msd81. Anyone else try running b58s on the old msd80?

[@JerainJezza]

Is it because of upgraded coils?

[@guillermoortega6802]

The anti-theft system on my 2008 328i activeted it cranks but won't start I can't drive it anywhere help please

[@jesusramirez3123]

What happen when you are changing the sparkplugs and by accident you hit the positive pole and get sparks my car cranks but won't start thank you

[@Strassenpraktikant]

These one work on n53? I ordered

[@SupraSav]

Just a heads up your local electronics/PC repair shop should be able to switch mosfets for anyone that's looking

[@megamaury23]

install diff brace for better grip

[@2jzking124]

Hi Your video are amazing!!! I need to ask you something, is there any way to get in touch with you? Please let me know

[@simonebellone4158]

0029DD DME: detection of bad roads BMW E65 740i. the motor when it is cold has no power after about 5 minutes it recovers 🤷🙏

[@AshByad]

Will i lose my mhd map if i upgrade to msd81 ? Btw great video and great DIY

[@scottxp800]

From what I understand MHD updated to use the CAS vin number so a DCM module change won't keep you from using MHD. It was a problem in the past...

[@AshByad]

Scott Gaines thank you for the info

[@derrikwilliams8691]

5 mosfets in my dme failed. I replaced all 6 myself (with your help) I also installed the 3.5 bar tmap and wired socket accordingly (also with your help) I get everything back together and engine turns but won't fire. Turn car on with kdan to mhd and it brings up main menu fine but when I select a option is Saya cannot detect cable. Did I fry dme??? Your thoughts if any I would love to hear. Mhd 2+, fresh coils, index 9 injectors

[@bondjamesbond2849]

Check ignition fuses, fuel fuses, injector connections ect

[@santtu9169]

Have you recieved your custom tune? And what about that after market LSD, any sign of wear or tear?

[@VehicularDIY]

Yeah I have received my 2nd iteration of my custom tune. The LSD is holding strong so far, I haven't noticed any degradation.

[@rickys.creations1120]

? On the mosfets upgrade do you need to do any flashing the the ecu or is it plug and play meaning put on and start the car?

[@VehicularDIY]

Yeah once you're done you can start the car, no flash updates required.

[@jasonspitzley1004]

The msd81 is not exempt. But it does make it where you can pickup a nice car for little money. 🤷🏻‍♂️

[@hemnhemn5761]

👍👍👍👍👍👍👍👍

[@charlybouaoun1054]

I have the same problem with my n52 i have upgraded the mosfets it lasted me 10 days then the problem happened again note i have al bmw 6 coils

[@FrankBernal24]

So I got the mosfets replaced at local shop. Codes are gone except now I have p0174 and misfires on 4,5,6. Any idea? Did smoke test and no vacuum leak. Changed plugs and switched coils around. Only thing left to do is fuel injectors. Do you think possibly the shop installed one of the mosfets wrong?

[@Robertwinco]

Did you make it?

[@ChrisChaos209]

🤘🏼

[@RDTengineered]

More on what high power mosfet could be used. See trace showing 380V is reached(Probably on a stock car): bimmerprofs.com/30ba30bb-repair-msd80/ +The IRF644 250V/14A is commonly sold as replacement :www.mouser.com/datasheet/2/427/sihf644s-1768609.pdf +In this video FDB14N30TM 300V/14A : www.onsemi.com/pub/Collateral/FDB14N30-D.pdf +Suggested from BimmerProf SiHB30N60 600V/29A: www.vishay.com/docs/91453/sihb30n60e.pdf +From my own search using BimmerProf suggestions of parameters. Maybe completely useless to go this high but, maybe on modded cars trying to use ELDOR coils to the MAX??(ME not EE use at own risk): NTB095N65S3HF 650V/36A www.mouser.com/datasheet/2/308/NTB095N65S3HF-D-1539963.pdf I have not had the originals fail on my 07 with 180K yet...

[@fedejunin]

I have the error BB30, i took the DME and I checked the mosfets, i got this numbers in all 6: drain-source 374 K ohms , drain-gate 0.885 M ohms. Does someone know if they need to be replaced?

[@ricardodupont1170]

Someone?

[@Omar92Canada]

My 335! X6 has a misfire #3 after my brother accidentally ripped the brown wire that goes to the coil #3, we fixed it properly and checked the coils & injectors..ect the ( we checked #3 plug by Voltmeter and it reads 15V) while the rest lower around 11Vot?? And Still no spark! One guy said it need a new ECU/DME wich I don't think so, now I'm expecting the problem would be a burned (MOSFETS) but I sent the car to BMW service yesterday for final inspection to be sure, let's see what they say, Actually I hope they say you need a DME so I can smile and leave and start the process of changing the MOSFETS.

[@justinr9783]

Omar Al-azawi did they ever tell u what happened

[@FerasDishli]

My friend, the air filters position are not good at all, they take the hot air from engines bay. Try to find a solution to get the air from out side the engines bay. It must be a better air intake for your car in aftermarket, good luck 🍀

[@X11CHASE]

So sick of seeing these stupid ass comments about air filters on intercooled cars

[@ni3k777]

I drive a 07' 335i that is running MSD80 with an 30BB injector x,y,z order DME, internal error. Bank 2 is misfiring. The MOSFET's tested fine, anyways I upgraded them. The error remains. I ruled out the injectors by upgrading to index12 and a ground by doing a noid light test. No signal or light is seen on injectors 4-6, which is so post to indicate that injectors 4-6 are not receiving signal. Anyone familiar with the MSD80 board that can help me trace the problem? I was considering upgrading to a used MSD81, however, I need to find a reliable vendor then code the UIF to add a secondary VIN (mine). Meaning I would have to be fine with the primary VIN (donor) on the DME.

[@fideldiaz2625]

What was your problem did you ever figure it out ? I’m having the same issue

[@ni3k777]

​@@fideldiaz2625 I changed the MOSFETS. The problem remained. I did a DME swap with a third party. Immediately solved. I can give you their number. He's direct and answers all questions. DM me for his number. You would mail your DME and CAS to their address.

[@rustedratchetgarage6788]

328s also suffer from this issue