[kiteboy]

how it is possible that a transistor failure ? like this ????

[joec500]

Originally Posted by kiteboy

how it is possible that a transistor failure ? like this ????

Bad production batch?

[747chris]

This post certainly was a huge money saver. Replaced all six transistors and she is once again purring like a kitten(or should I say roaring like a lion). I got a tv repair shop in Burbank, CA (Arc TV Thanks Bill!) to replace all six transistors for $45. The transistors cost me a whopping $1.06 each! Might just use the money I saved for an LSD.

[Antonio91]

i this site do i pick part number FDB14N30TMCT-ND or FDB14N30TM these are under the drop down window "item number"
http://www.digikey.com/product-detai...MCT-ND/1566830

[747chris]

I got FDB14N30TM from Mouser Electronics.

[Antonio91]

Originally Posted by 747chris

I got FDB14N30TM from Mouser Electronics.

thanks will order tomorrow

[007_e350]

Just out of curiosity, I have the Open Flash Tablet and I keep flashing my DME with different maps .... would it in anyway reduce the life of those components or make them vulnerable to get fried ? ... also aggressive maps can fry the mosfets ?

[Roy Cormier]

Flashing the DME shouldn't have any negative impact on those components.

[EASTCOASTNINJA]

Originally Posted by Roy Cormier

So a couple weeks back I was out for a nice Sunday drive in my 335i, I downshifted into 3rd, floored it, and heard an insanely loud backfire. Then that damned half-engine light comes on and the car barely makes it home.

After reading the codes with the Cobb Accessport I decided to probe the pins on the DME connector to try to figure out what was going on.

The Transistor for injector #5 was toast, and after I saw what a replacement DME would cost from the dealer I figured I better just fix it myself. I took the part number off the MOSFET, spent $2.00 for a new one from digi-key and after a little bit of work with the hot-air gun I was back in business.

I was getting the following codes:
30bb - DME digital motor electronics, internal failure
0305
0306
0304
0300
29d1 - Misfire Cyl 5
29d2 - Misfire Cyl 6
29d0 - Misfire Cyl 4
29d9 - something about misfiring with low fuel level
29cc - Misfire Multiple Cylinders



So heres a few pictures in case anyone is unfortunate enough to have a similar problem occur.








Transistor pins were shorted together








I stopped taking pictures after this point. But basically the old transistor was removed and replaced with a new one.


Then after everything was closed back up, it started and ran great.

So i think i fell victim to a fried DME as well same symptoms and everything. i bought all new coil packs and 3 new injectors for cylinders 4,5,6 and installed INPA and ran the diagnostic and still had misfires and code 30BB so after reading this i contacted N54DME.com and they will repair my ecu for $500 with warranty. so im gonna do it. any advice before i do this guys?

[AWTT335i]

$500 for a part that costs less than $2. Ouch. Why not see if a local electronics shop will solder the new MOSFET in?

[Aced16]

Can anyone verify that these also regulate voltage to the post cat o2 sensors? I have an o2 sensor that is currently sticking at .41v and when I check the resistor through actual values with the BT Tool, its showing 65k ohms while the other bank shows 0.

[RadiuM]

Anyone had these issues on a MSD81 ?

[007_e350]

Heys guys I'm be opening up my DME but not for injector / coil related issue - I fried it trying to flash it (used wrong software version (DME is IJEOS, I flashed with I8AOS), now DME doesnt communicate thru INPA nor the openflashtablet ... any advise on which MOSFETs / components to look at ? Anyone has the circuit diagram for the DME 81 ?

[dbudh001]

i suck at things like this, but i wanted to test my MOSFETs just to ensure they are or are not a part of the issue, can you give me the steps on how you test them, i know there was a youtube video posted, but i dont know what tool to use , or what settings to use,
i was googling it but all the sites stated i need to know voltage, and some other crap ...

[._.]

use a voltmeter, check continuity between the source and drain of the FET. I.E. the voltmeter should not beep when you touch the two legs.

[dbudh001]

Originally Posted by ..

use a voltmeter, check continuity between the source and drain of the FET. I.E. the voltmeter should not beep when you touch the two legs.

not to be the dumb a$$ of the bunch , but what should the dial be set to ?

[crypticc]

Ohms resistance bottom left use common COM for black cable and middle hole for red. Touch your two cable together briefly while not connected to the circuit to read what `short circuit` looks like. and then put your red on source and black on drain must like on the picture. I'd it looks same as when you touched the cables together then your transistor is burned out (flows freely even without switch signal applied to the third pin)

[big_c]

Originally Posted by ..

mine occurred right after installing my Jb4 G5 ISO as well, after a few 3rd gear pulls, loud pop and that was that.

Really weird...I suspect I am in the same boat as you guys...trying to diagnose now. Getting tons of misfires and car barely idles .

I wonder what it is about tuning and the transistors giving up the ghost. Maybe it just puts too much strain or heat on them being open for longer...and the weak early version transistors can't take it. Stock they are fine because of lower injector pulse width...just a theory

[sleepysvt98]

My tech @ BMW is currently trying this process, hopefully it works for me as well. Great write up BTW!

[crypticc]

Originally Posted by crypticc

Ohms resistance on meter are bottom left connectors; use common COM for black cable and middle hole for red. (Additional note pick low resistance setting to keep the current levels low in the meter)

Touch your two mater cables together briefly while not connected to the circuit to read what `short circuit` looks like.

Then to take the reading put your red on source and black on drain just like on the picture. If it looks same as when you touched the cables together then your transistor is burned out (the test will have confirmed current flows freely even without switch signal applied to the third pin)

Blimey! I just realised what my keyboard auto correct did to my typing. Sorry.

Corrected above.

[tjobeid]

i ordered these! hopefully its the right ones.
- FDB14N30TM

http://www.globalspec.com/specsearch...6&regevent=new

[TeinBMW]

Sweet great work man!