Misfire Cyl 1

N54Yankee · 03-13-2020, 03:01 PM

Day before yesterday I stomped the throttle in my 2010 N54 135i and immediately got a service engine warning on display, a misfire and limp home power mode. Next day the service engine soon was gone and full power restored.
I plugged my code reader in and did a full scan. What came up was, DME COMBUSTION CYLINDER 1 MISFIRE.

Seems #1 cyl mosfet in the DME went kaput. I really don’t want to fork over about 500 bucks or more for a new one but I seem to recall that one can remove the DME and ship it somewhere who replaces the dead mosfet for a reasonable price. Does anyone know the name of the name(s) of business who does this work on BMW ECU’s? Thanks

Edrift · 03-14-2020, 02:17 AM

How are you sure it's the MOSFET and not a flakey coil or plug?

N54Yankee · 03-14-2020, 08:58 AM

Quote:

Originally Posted by Edrift

How are you sure it's the MOSFET and not a flakey coil or plug?

My vehicle specific code reader told me. Not that makes me sure and it would be wise to verify that. Thanks

Jeef · 03-14-2020, 09:41 AM

Quote:

Originally Posted by N54Yankee

Quote:

Originally Posted by Edrift

How are you sure it's the MOSFET and not a flakey coil or plug?

My vehicle specific code reader told me. Not that makes me sure and it would be wise to verify that. Thanks

I want a scanner that can tell me if my mosfets are going bad. what do you have? lol

first step is to do basic diagnostics. then go from there. DME should be looked at last unless you have a bank misfire.

N54Yankee · 03-14-2020, 10:53 AM

Foxwell NT510 Vin specific scanner.
It initially gave me the problem, DME: Combustion misfire cyl 1, it also gave me the part number of the offending part, hardware version, even the date of manufacture of the unit. It also gives the physical hardware number.
Doing a quick search I see it’s a frequent problem with BMW DME mosfet failures.

03-13-2020, 03:01 PM	#1
N54Yankee Lieutenant Colonel 2707 Rep 1,916 Posts Drives: N54 135\|Cobb\|M3 control arms Join Date: Sep 2018 Location: USA iTrader: (0)	Misfire Cyl 1 Day before yesterday I stomped the throttle in my 2010 N54 135i and immediately got a service engine warning on display, a misfire and limp home power mode. Next day the service engine soon was gone and full power restored. I plugged my code reader in and did a full scan. What came up was, DME COMBUSTION CYLINDER 1 MISFIRE. Seems #1 cyl mosfet in the DME went kaput. I really don’t want to fork over about 500 bucks or more for a new one but I seem to recall that one can remove the DME and ship it somewhere who replaces the dead mosfet for a reasonable price. Does anyone know the name of the name(s) of business who does this work on BMW ECU’s? Thanks __________________ __________________ "The Constitution was never construed to authorize Congress to infringe the just liberty of the press, or the rights of conscience; or to prevent the people of the United States, who are peaceable citizens, from keeping their own arms.” Samuel Adams Last edited by N54Yankee; 03-13-2020 at 05:29 PM..
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03-14-2020, 02:17 AM	#2
Edrift Private First Class 75 Rep 187 Posts Drives: BMW 135i E88 Join Date: Jun 2019 Location: Melbourne Australia iTrader: (0)	How are you sure it's the MOSFET and not a flakey coil or plug?
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03-14-2020, 10:53 AM	#5
N54Yankee Lieutenant Colonel 2707 Rep 1,916 Posts Drives: N54 135\|Cobb\|M3 control arms Join Date: Sep 2018 Location: USA iTrader: (0)	Foxwell NT510 Vin specific scanner. It initially gave me the problem, DME: Combustion misfire cyl 1, it also gave me the part number of the offending part, hardware version, even the date of manufacture of the unit. It also gives the physical hardware number. Doing a quick search I see it’s a frequent problem with BMW DME mosfet failures. __________________ __________________ "The Constitution was never construed to authorize Congress to infringe the just liberty of the press, or the rights of conscience; or to prevent the people of the United States, who are peaceable citizens, from keeping their own arms.” Samuel Adams
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