BMW M5 Forum and M6 Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter #1 (Edited)
After driving roughly 40 miles my SES light came on. Plugged in the peake tool and received Fault 10(crankshaft sensor) AE/AF(Air Fuel Adaptation Cyl 1-4 and 5-8)

Is the AE/AF code normal after doing this?
 

·
Registered
Joined
·
3,873 Posts
No.

But I would check and make absolutely sure that you connected the intake piping together completely. I would also try resetting the codes and see what comes back. If your MAFS were that bad, it may take a while for the DME to adjust everything back into normal parameters. In the meantime, some test results may be out of tolerance.
 

·
Registered
Joined
·
12,398 Posts
If your DME maps were very distorted due to bad mafs, when you slap the new ones in the DME can have issues. It is recommended to resent adaptations by disconnecting the DME for a while.

But as mentioned above, doublecheck your connections - elect and air- to the MAFs....
 

·
Registered
Joined
·
30 Posts
Discussion Starter #4
took apart everything, put back together nice and snug and reset the code. Went on a 20 mile drive and no SES light yet...I'll reset the DME as well and hopefully SES light stays off!
 

·
Registered
Joined
·
37 Posts
Hi, any conclusion to this?

I've just replaced my MAFs after a very low l/ph reading and occasional misfire above 4k rpm and hesitancy.

All was fine for about 40-50 miles then I got the yellow check engine light. INPA says the codes are:

1) Minimum flow of secondary air (error occured several times between 680rpm and 1600rpm)
2) Misfire cyl 1 (error occured several times above 5400rpm)
3) Misfire cyl 6 (ditto)
4) Misfire of multiple cyls (also above 5400rpm)

Really annoying tbh, I've only recently got this M5 and it's just had a big service, clutch and MAFs.

I think in INPA I have the ability to reset adaptation values - is this wise? Has the DME just not got used to the new MAFs yet? It was running really well straight after the new MAFs.

Any help appreaciated :)
 

·
Registered
Joined
·
10,265 Posts
I would be looking at injectors for your codes. I may change my mind after a couple of questions. Is the AA code new? Have you every run injection cleaner thru a tank of gas? What are your L/H results like now?
 

·
Registered
Joined
·
10,265 Posts
Thanks for the reply. I'm not sure what you mean by AA?
Sorry the AA code is the hex number for minimum air definition you gave. The DME reads a post cat o2 sensor to determine if there is enough air. If there is unburned gas from leaky injectors that air gets used up in the cats.
 

·
Registered
Joined
·
6,642 Posts
Forget the secondary air code for the moment...Most likely carbon build up,anyway..

Swap ignition coil 1 to cylinder 2 and see if error follows.if not,do the same with the spark plug.

Do the same on the other bank.

Mis-fire at high rpm is very often plug/coil related on these engines...


INPA can reset adaptation values.
 

·
Registered
Joined
·
10,265 Posts
Forget the secondary air code for the moment...Most likely carbon build up,anyway..

Swap ignition coil 1 to cylinder 2 and see if error follows.if not,do the same with the spark plug.

Do the same on the other bank.

Mis-fire at high rpm is very often plug/coil related on these engines...


INPA can reset adaptation values.
Your right forget the AA. What do one and six have in common? The flywheel. From your post on Waynes

2 crank rotations means one full cycle...

So bent teeth show on cylinder x and cylinder y(that is 360deg crank away from cylinder x in the ignition cycle) the exact same issue...

Given it is cylinder 5 that is the issue,problems with the fly wheel would also show up on cylinder 3,given the firing order:1 - 5 - 4 - 8 - 6 - 3 - 7 - 2
1 and 6 right. What else could do that? I agree switch a coil as the first test.
 

·
Registered
Joined
·
37 Posts
Flywheel :eek: lol.

It's just had the clutch done and the flywheel was apparently fine. It's on 99k btw.

I was about to swap the coils but then seeing it was a little more involved than swapping coils on my 530 I decided to take it for a spin just in case the car was getting used to the new MAFs. I'd already cleared the old codes and drove about 30 miles today, taking it to the redline quite a bit, in the name of research obviously.

No fault code, no check engine light.

I'm still not 100% confident that it's ok, but it was certainly in good health today. If it happens again I'll swap a coil.

Thanks for the help guys, and if anyone else has any other ideas I'd love to hear them :)
 

·
Registered
Joined
·
10,265 Posts
It could be dirt on the flywheel especially since you just did the clutch. If no cel i would not worry. Probably will go away. I thought you had a cel.
 

·
Registered
Joined
·
10,265 Posts
I did not have time yesterday to explain. The flywheel has the timing teeth on it. The way a misfire is registered, is a measure of those teeth accelerating. So when the misfires are the same teeth it is a very likely they are causing the register. Consider this a timing error. The engine spins twice for a cycle but the flywheel is only one, so the teeth are shared by two cylinders for timing. 1 and 6 are the same teeth, as are 5&3,4&7, and 8&2.
You just had your clutch done it is possible that something got on it or a tooth got a whack. You seem to only have them at high rpm so it could be very slight imperfection that the crank sensor only has difficulty at that faster cycle. When the cycle is slow it can register the teeth correctly but as it spins faster it has a had time.
 
1 - 13 of 13 Posts
Top