check engine light? but no codes?

So i have an 07 e90 335i. When i floor it, once i get the revs up to around 5k the CEL comes on.
It stays on until i turn the car off and when i turn it back on there is no light until i rev it past 5k again. (If i sit still in park and rev the light wont come on, only if i actually floor it while driving)

Also, if i dont turn the car off, while the CEL is still on, if i plug in a scanner it says the CEL is NOT on (when i can see it is) and that there are NOT ANY CODES coming up. (tried multiple scanners)

Anyone who is familiar with the N54, please tell me if you know why this is.

Also, when the light comes on, i dont lose any power (no limp mode), i can still drive as fast as i want.
Im doing spark plugs tomorrow, hopefully that will fix it.

If you have any ideas why this may be happening, please let me know! Thanks!

Apparently you are getting a 'soft' fault which is not memorized by the computer, something I did not think was possible any longer. On the other hand it may be a case of "What we've got here, is failure to communicate." Is your scanner capable of picking up codes other than P codes, like B codes for instance? Does your scanner read BMW specific codes or just P codes?

Originally Posted by DSXMachina

Apparently you are getting a 'soft' fault which is not memorized by the computer, something I did not think was possible any longer. On the other hand it may be a case of "What we've got here, is failure to communicate." Is your scanner capable of picking up codes other than P codes, like B codes for instance? Does your scanner read BMW specific codes or just P codes?

One scanner that was used was one of those expensive 1000+ dollar scanners that a pro mechanic had. Though i know money isnt everything, i was assuming his scanner had the ability to pick up any and all codes.

The second was a cheaper scanner that my friend, who is a mechanic at jaguar uses. He works on BMWs daily so i assumed he wouldve known about P and B codes (though i do not know about either).


Anyway, the reason i am changing the spark plugs is because i saw a youtube video of a guy going 150 some in his 335i and then got a check engine light. a few months later he commented that it was only spark plugs and the CEL was no more. He also did not go into limp mode, and had full power.

I hope i gave you enough information.


PS funny youtube video you included =D


EDIT: The scanner my friend who works at jaguar used was his personal scanner at home, not an actual jaguar scanning device.

Originally Posted by Zain1003

One scanner that was used was one of those expensive 1000+ dollar scanners that a pro mechanic had. Though i know money isnt everything, i was assuming his scanner had the ability to pick up any and all codes.

BMW has many proprietary codes, meaning that a code can be read, but nobody knows what it is unless a code table's made available.

THIS scanner tells all.

Originally Posted by CALWATERBOY

BMW has many proprietary codes, meaning that a code can be read, but nobody knows what it is unless a code table's made available.

THIS scanner tells all.

Very good device Cal, it's much more than a scanner of course with its graphing ability and all. This is one tool to own for anyone interested in doing real troubleshooting on their own BMW.
I have to say it's also dirt cheap! For that kind of power a shop would pay thousands of dollars. The difference though is that for $298 you get only 3 VINs. That would last a morning at my shop. For much more they'll give you limitless VINs.

Originally Posted by DSXMachina

Very good device Cal, it's much more than a scanner of course with its graphing ability and all. This is one tool to own for anyone interested in doing real troubleshooting on their own BMW.
I have to say it's also dirt cheap! For that kind of power a shop would pay thousands of dollars. The difference though is that for $298 you get only 3 VINs. That would last a morning at my shop. For much more they'll give you limitless VINs.

Note the claim that it does everything a GT1 does. Sweeet.

OP: The advantage to the BT cable is of course the database made available over the Internet, and importantly, the ability to change settings, knowing what each location does.

Otherwise just search for BMW codes and you'll find any number of conversion tables.

Bon Voyage!

Originally Posted by CALWATERBOY

Note the claim that it does everything a GT1 does. Sweeet.

OP: The advantage to the BT cable is of course the database made available over the Internet, and importantly, the ability to change settings, knowing what each location does.

Otherwise just search for BMW codes and you'll find any number of conversion tables.

Bon Voyage!

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Ugh i really dont want to drop another 300 =(. we'll see.

Does anyone have any idea on what it could possibly be though?

Oh also, will a JB4 read the code for me? i saw a post on a similar topic and it seems terry is indicating you can have the code identified by the jb4. if so, ill just spend 500 bucks on that than 300 on that scanner. (excuse to buy a jb4 yay!)