[Roy Cormier]

Originally Posted by thetedderbear

I'm assuming you just soldered the new one on?

Since the transistors are surface-mount they have to be removed with a hot air gun, then the new ones are soldered in place using the same tool. Its' a lot more work than traditional soldering, but not too bad once you get the hang of it. You've just got to be careful to not put too much heat into the surrounding components, as they're only rated to handle a certain peak temperature for a short period of time.

Originally Posted by wizoneway

Was the root cause of these DME failures a bad coil? Today my #3 went bad and allegedly caused a short frying the DME. 6CP's, plugs, new DME for $3k

From what i have ascertained from the dealer, they will need to program a new DME by pulling from the burnt DME, meaning they can still communicate with it. Why would they program a new DME ('07 build) with the old?

Is it a possibility that some transistors need to be replaced?

In my case it was a wiring problem. But I think it could be caused by components failing as they age, or possibly issues with coils.

[EricBrazil]

Roy,
transistor IRF644 is compatible with IRF644B?

thank you

[EricBrazil]

congratulations!!!!!!

[Roy Cormier]

Originally Posted by EricBrazil

Roy,
transistor IRF644 is compatible with IRF644B?

thank you

You'd need to compare the datasheet to the IRFW644B datasheet to know for sure.

Theres a copy of the IRFW644B datasheet here: http://roycormier.net/download/irfw644b.pdf

[EricBrazil]

Originally Posted by Roy Cormier

You'd need to compare the datasheet to the IRFW644B datasheet to know for sure.

Theres a copy of the IRFW644B datasheet here: http://roycormier.net/download/irfw644b.pdf

Roy, thank you!!!!



not compatible,you agree? has the purchase link??

thank you

[K.david]

If you drive an 07 you may have fell under warranty for a bad component in the DME. There is a service bulletin out there. It is a small production range. Those codes look familiar. I think it was a bad diode. They would have replaced the DME. Excellent work though.

[EricBrazil]

my car is 09, I think the problem is in the injectors.... misfire injector6.

[tjobeid]

Originally Posted by maibuN

Thank you very much!!! I had the same problem. I replaced two transistors and my DME works again.

Could this problem be related to tuning? My dme crashed instantly after updating to the JB4 G5 iso firmware.

Would it make sense to replace all transistors to avoid that problem in future? At the moment i only replaced the two damaged transistors.

how could you tell which 2 were damaged ?

[s2k_335i]

If you have time, I can ship you the DME/ECu and ill pay you for your time.

[minimac21234]

This is a quick video I just took of how I believe to diagnose the bad mosfets on the MSD80 DME. It might not be correct as far as diagnosis or terminology, and if so, please let me know and I will remove the post. Just looking to help the community.

-Mike

[Rickygst]

good job, I would have never attempted this. But glad someone out there can do it.

[minimac21234]

Just wanted to say thank you to all involved that collected all the information needed to fix this. I was able to successfully replace the bad transistor with a heat gun and reapply a new one with the heat gun. Reflowed the solder, changed out the bad coil pack, and presto, all set and running like a champ. Thanks again everyone!

[Kuch335]

Originally Posted by minimac21234

Just wanted to say thank you to all involved that collected all the information needed to fix this. I was able to successfully replace the bad transistor with a heat gun and reapply a new one with the heat gun. Reflowed the solder, changed out the bad coil pack, and presto, all set and running like a champ. Thanks again everyone!

What parts did you get and where from? Need to do this to mine now.. got all these codes (below) Saturday and the 30BB comes back as soon as I clear them with the JB4 w/o the car running, so looks like DME for sure. I searched for the IRF644S part and all i can find are the RoHS replacements (IRF644SPBF).. should this work?

http://www.mouser.com/Search/Product...844-IRF644SPBF

30BB DME digital motor electronics, internal failure
2D60 Fuel mass, monitoring
29D0 Misfirings, cylinder 4
29CC Misfirings, several cylinders
30FF Boost under target -- possible boost leak

I guess I could take it in under the 8yr/80k emissions warranty but if I can swap a few $2 chips, its worth not having to de-mod with downpipes.

On the bright side, this is a good time to send out the JB4 for G5 ISO

[shoepac11]

Just Had exact issue on my 2008. Stealership actually waranteed the DME, however I had already looked into repairing board. As for replacing components on a circuit board, do yourself a favor and get a decent soldering iron, and most importantly a push button "solder sucker" from radio shack. The RS employees will know what you are talking about. And don't be scared of the job. The vast majority of people out there would probably think that the job would be too complicated, but replacing components on a CB is actually pretty simple and straight forward.

*what you will need (typically)
- Replacement Parts
-Soldering Iron
-Solder (i prefer flux core for stuff like this)
- Solder Sucker
- Wet Sponge
- Dykes & small Needle Nose Pliers (depending on config)
-Good light

**Component Removal**

1. find component to be replaced.
2. Locate correct pins if they go through to the back side of CB.
3. Get solder sucker "cocked and ready"
4. Melt solder with soldering iron.
5. While soldering iron is in contact with solder keeping solder melted, put the tip of the solder sucker right down against the board over the pin or immediatly around the pin, and push the button that "fires" the sucker.
6. Repeat step 4 and 5 for all pins of component.
7. Gently remove component. (may need to remove more solder or just heat a pin or 2 while removing component)

**Component Installation**

*Steps 2 and 3 of installation should be done swiftly and carefully as to not heat the circuit board too much. If the Soldering Iron is left against the CB too long it can over heat the board and release the bond between the copper ring and the board itself. Don't let this scare you out of attempting this task, just be aware that if you leave the soldering iron against the copper ring for a few seconds and the new solder doesn't melt against it, then the iron is not hot enough, or the iron is too dirty. Iron can be cleaned up using a wet sponge. always good to have one handy anyways when soldering.

1. Place replacement component in original location. (pins may need to be bent or trimmed, depending how original component was installed. you be the judge.) However if the new component has long leads, and they are to be soldered to the backside of board. it is a good rule of thumb to leave the leads long until the component is soldered into place. Then trim off the leads as close to the new solder as possible.

2. Place hot soldering iron lightly against copper ring on CB for a few seconds. Gently touch solder to copper ring. Melted solder should very quickly fill hole and surround pin. (If not, clean iron, wait a few minutes and try again.)
3. Repeat step 2 for all component pins.
4. Trim leads if/as nessasary.

******DON'T GUILD THE LILY!!!!******** - Unless you are "ARE" a professional, YOU ARE NOT A PRO. If a solder point is good, but not PERFECT, do not ' attempt to make it perfect. Just because it does not look like factory does not men it's not effective. The more you mess with it, the more chances that you may burn the CB, or something else disastrous. You will regret it.

GOOD LUCK!!

[chris98m3]

I think my dme just fried I am getting 30ba
2a2b
29ce
29cf

I changed 3 injectors. All spark plugs and I changed my coils like 6 months ago but I changed back to the old ones and still misfire in only 1 2 n 3
My car is a 335i e90 07 made in 06 or October

[chris98m3]

where can i get the MOSFET. every where i look its they dont sell it anymore

[chris98m3]

Is this the right part IRF644B_FP001

[Kuch335]

Originally Posted by chris98m3

where can i get the MOSFET. every where i look its they dont sell it anymore

They don't make the IRF644B any more. This is the part you want. I replaced all 6 of my injector mosfets to make sure it didn't happen again. They worked perfectly.

http://www.digikey.com/product-detai...MCT-ND/1566830

[chris98m3]

Thanks for all the help. My car is fixed.

[Kuch335]

Originally Posted by chris98m3

Thanks for all the help. My car is fixed.

Awesome, congrats. Can't beat the price for what would have probably turned into 2k at the dealer if you went in with mods. From what I heard from my service rep they will replace all the plugs, injectors, and coils before even looking at the DME.. Even though the error codes clearly say DME failure .. and they would never touch mosfets, you would just get a new DME. It's a roll of the dice, if you get the DME covered under emissions warranty, you get a new one and all new coils, injectors and plugs for free.. I just didn't want to de-mod.. not worth my time..

[chris98m3]

Originally Posted by Kuch335

Awesome, congrats. Can't beat the price for what would have probably turned into 2k at the dealer if you went in with mods. From what I heard from my service rep they will replace all the plugs, injectors, and coils before even looking at the DME.. Even though the error codes clearly say DME failure .. and they would never touch mosfets, you would just get a new DME. It's a roll of the dice, if you get the DME covered under emissions warranty, you get a new one and all new coils, injectors and plugs for free.. I just didn't want to de-mod.. not worth my time..

Same here. I didn't want to take all the mods out and on top of they they would have the car for a couple of weeks.

[joec500]

Originally Posted by Kuch335

They don't make the IRF644B any more. This is the part you want. I replaced all 6 of my injector mosfets to make sure it didn't happen again. They worked perfectly.

http://www.digikey.com/product-detai...MCT-ND/1566830

Sweet I ordered a set just in case my DME ever blows, it will be nice to have the piece of mind of having these in my toolbox.