[E92_adrian]

So I took my car to the shop and they told me that my car is misfiring because the dme had a problem where it won't trigger cylinder 4 to 6 so it's working on half the cylinder, he said in order to see if they can repair the dme he would like to send it to AA in miami, however they'll charge 400-500 to fix it, I looked online for the cost of a new dme and I keep seeing them on websites for around $170, would these work on my car? Am I missing something?

[andydna15]

What codes are you getting ?

[jgoens]

Originally Posted by E92_adrian

So I took my car to the shop and they told me that my car is misfiring because the dme had a problem where it won't trigger cylinder 4 to 6 so it's working on half the cylinder, he said in order to see if they can repair the dme he would like to send it to AA in miami, however they'll charge 400-500 to fix it, I looked online for the cost of a new dme and I keep seeing them on websites for around $170, would these work on my car? Am I missing something?

Didn't you recently install a jb4 and have issues with the install? If that was the case, I would remove that and see if it runs normal.

[techwhiz]

Originally Posted by E92_adrian

So I took my car to the shop and they told me that my car is misfiring because the dme had a problem where it won't trigger cylinder 4 to 6 so it's working on half the cylinder, he said in order to see if they can repair the dme he would like to send it to AA in miami, however they'll charge 400-500 to fix it, I looked online for the cost of a new dme and I keep seeing them on websites for around $170, would these work on my car? Am I missing something?

The typical DME failure is the output transistors.
See: http://www.e90post.com/forums/showth...&highlight=DMe

[jtswole]

Check the injector mosfets on the dme.

[Roy Cormier]

Originally Posted by E92_adrian

I keep seeing them on websites for around $170, would these work on my car?

Probably just bad MOSFETs which is a cheap fix. But to answer the other question, yes a DME from another car will work, but only if you have the matching CAS and Key-Fob. They all need to match. I was going to look into making them work without a matching CAS, maybe when I get bored this winter.

[332ijunkie]

Im sure a member here would fix for <600$.

[///Mposter]

Some people have said they have taken it to a TV repair shop, an aviation repair station that does avionics or a friend that has great soldering skills.
If you read the link that was posted earlier, you can buy the mosfets for cheap. Buy more than 6 just in case one gets messed up or whatever. They will charge you about $50-$100 .
Word of advice though when asking them if they can do it. Do not say it is for a car. Just ask how much to replace 6 surface mount mosfets. Someone said they got spooked by it being a car computer. They didn't want the liability. If anything , say it's for a track only race car . Best of luck.

[WedgePerformance]

I replace Cyl 1 MOSFET 3x in the past week. Customer car just installed TFT and RR550s. Replaced the first one and the car ran fine for 10 miles and then threw codes. Replaced it again, same thing 10 miles and codes. So we replaced the injector and MOSFET again, all good, but now misfire and cyl 1. Car ran like $#!7.. Replace the coil pack and all was good again. Car is a beast and I was able to drive it around without any codes or misfires.

[jtswole]

Originally Posted by WedgePerformance

I replace Cyl 1 MOSFET 3x in the past week. Customer car just installed TFT and RR550s. Replaced the first one and the car ran fine for 10 miles and then threw codes. Replaced it again, same thing 10 miles and codes. So we replaced the injector and MOSFET again, all good, but now misfire and cyl 1. Car ran like $#!7.. Replace the coil pack and all was good again. Car is a beast and I was able to drive it around without any codes or misfires.

When the injector mosfet goes, It usually takes out the injector and/or coil in that cylinder, also.

[E92_adrian]

Thanks for the info guys, I did replace all 6 coils and plugs and the problem persists, I did suspect it's a computer issue because my rpms bounce up and down randomly while the car is on idle and I get an A with a circle that has an arrow around it.

[BlackBB6]

Is this still limited to the DME's in the 07 models or have the newer ones started failing too?

[jtswole]

Originally Posted by E92_adrian

Thanks for the info guys, I did replace all 6 coils and plugs and the problem persists, I did suspect it's a computer issue because my rpms bounce up and down randomly while the car is on idle and I get an A with a circle that has an arrow around it.

Need to check the mosfets for continuity. If there is, the mosfet is bad.

[WedgePerformance]

Originally Posted by jtswole

When the injector mosfet goes, It usually takes out the injector and/or coil in that cylinder, also.

Yeah, that seems to be the pattern.

What would be even more frustrating is if you had to send your ECU for repair and it fail again because of this after getting it back a week later.

One reason I don't like doing this repair. There is no guarantee it won't fail again if you don't take the corrective actions.

[E92_adrian]

Originally Posted by WedgePerformance

Yeah, that seems to be the pattern.

What would be even more frustrating is if you had to send your ECU for repair and it fail again because of this after getting it back a week later.

One reason I don't like doing this repair. There is no guarantee it won't fail again if you don't take the corrective actions.

Do you think if I took off the jb4 it would stop this issue from happening?

[AWDBooSTIn90]

If you had the jb4 on for awhile and the car ran fine then its not jb4 related most likely. Like everyone said check the injector drivers (mosfets).

Search on the forum for it and theres a great guide on how to locate them, how to check them, what to order, and how to replace them if you can do circuit board soldering type work. It's definitely alittle more tough and involved than just soldering wires together.

EDIT: found the thread for you
http://www.e90post.com/forums/showthread.php?t=734162

[longnvu]

If you need your mosfet replace give me pm.

[jtswole]

When I blew a few mosfets, the only change that was made to the car before it happened, was installing a flash(from Wedge). It blew three mosfets 5 minutes after turning the car on and taking it for a ride. I think it has something to do with the increased injector DC, that blows them. I don't believe it has anything to do with what flash or tune you are using. When replacing them, make sure to use an experienced solder, that can solder very well.

[Jklad]

Originally Posted by jtswole

When I blew a few mosfets, the only change that was made to the car before it happened, was installing a flash(from Wedge). It blew three mosfets 5 minutes after turning the car on and taking it for a ride. I think it has something to do with the increased injector DC, that blows them. I don't believe it has anything to do with what flash or tune you are using. When replacing them, make sure to use an experienced solder, that can solder very well.

It happens to plenty of stock cars that were never tuned as well.

[WedgePerformance]

Originally Posted by jtswole

When I blew a few mosfets, the only change that was made to the car before it happened, was installing a flash(from Wedge). It blew three mosfets 5 minutes after turning the car on and taking it for a ride. I think it has something to do with the increased injector DC, that blows them. I don't believe it has anything to do with what flash or tune you are using. When replacing them, make sure to use an experienced solder, that can solder very well.

The increased injector DC is one reason. Like I indicated recently I replace cyl 1 twice only to have it fail within 10 min. Only after replacing the injector were we able to get the car running without blowing a MOSFET. We ended up having to then replace the coils as this issue seems to cause the coil to fail as well.

So, bottom line, if you have a blown MOSFET, and you have old injectors and coils, good opportunity to replace the injectors and coils. Might save you the time and headaches of replacing the MOSFET multiple times.

[cstmx_ryder]

Originally Posted by WedgePerformance

The increased injector DC is one reason. Like I indicated recently I replace cyl 1 twice only to have it fail within 10 min. Only after replacing the injector were we able to get the car running without blowing a MOSFET. We ended up having to then replace the coils as this issue seems to cause the coil to fail as well.

So, bottom line, if you have a blown MOSFET, and you have old injectors and coils, good opportunity to replace the injectors and coils. Might save you the time and headaches of replacing the MOSFET multiple times.

So how does one tell if it's indeed a MOSFET related issue? I'm leaning towards a electronic issue because I've exhausted all other options except replacing the injectors, until I saw this post.......Been at it for almost a year now, trying to get her to idle and run right......Also ready to switch tunes, but can't get any replies/answers from tuners.......

[RWDMIKE]

I've been through this issue before and have successfully replaced all 6 MOSFETs. I experienced issues after a Cobb Accessport was installed. I believe the issue is much more common after a tune has been flashed, but the reality in the whole situation is that it is a manufacturing issue from Siemens.