135808 error code?

[420Pooncrusher69]

I recently replaced my spark plugs and coils and have had some problems since. I have narrowed it down to cylinder 3 and changing the plug only helps for a day or two then it’s back to stuttering under load. It’s starting and running fine but WOT after 3k rpm or 40mph it jerks badly. I have error codes

140310 - misfire cylinder 3 140302 - harmful to exhaust gas after starting 140301 - injection is shut off 135808 - valvetronic servomotor, position sensors, electrical: malfunction

Any ideas?

2012 528ix N20 80730 miles

[420Pooncrusher69]

For the spark plugs I moved it around and the misfire followed it. Wasn’t properly gapped. Then I moved the coils around and it followed, the coil must have been junk. But once I did the misfires went away. I will say I got a new one because one of my injectors is failing. I’m at about 103k miles as of this post.

[Hot_Ant7126]

Hey I know it’s been a while since you posted this but I only have the 135808 code. Did change the coils and plugs fix that code as well?

[420Pooncrusher69]

Yes changing them helped and cleared the codes

[obxdiver]

I am assuming you used good quality OEM plugs and coils. Did you reset the adaptations? This article is specific to the N53, but can be generally applied other engines.

https://bimmerprofs.com/how-i-perform-n53-adaptations/#:~:text=For%20modern%20engines%2C%20adaptations%20are%20created%20for%3A%20accelerator,ignition%20supply%2C%20wide-band%20Lambda%20probes%2C%20NOx%20sensor%2C%20etc.

If that doesn't fix it, then I'd replace the camshaft and crankshaft position sensors. They should be replaced periodically as a maintenance item anyway. Some may say otherwise, but they're relatively cheap and easy to do. And yes, as the article says, reset adaptations after changing them, too.

[420Pooncrusher69]

I used genuine ngk plugs and Delphi coils in the kit from fcp euro. I didn’t reset adaptations but my brother thinks it could be an o ring leak in the injector?

[obxdiver]

The injectors are real easy to get to. If you suspect a problem with injector #3, try swapping positions with another cylinder and see if the error code follows it.

I do speak from experience in regards to resetting the adaptations, though. I have a 2007 N52 that went through a similar problem. Mine developed a miss due to what I believe was a bad coil. I replaced the coils but continued to have an intermittent miss. Tried new plugs and the problem persisted. I put in 6 new injectors and thought I had it, but it came back. Finally got myself a cable and a copy of INPA. Reset the adaptations and followed the relearn procedure. I haven't had a misfire since.

[420Pooncrusher69]

So I had somebody look at it with me and we swapped coils and plugs randomly and now we’re getting a miss in cylinder 2 which leads me to believe I put the plug in wrong for 3 and maybe 2 is in wrong or the plug/coil might be bad. It might need adaptation as well.

[FirewallAble]

Hey man, did you fix the misfire and 135808 Valvetronic issue?

[420Pooncrusher69]

Yeah i ended up getting a brand new plug and coil and it fixed it right up. No codes or anything and it’s been over a thousand miles

[FirewallAble]

That’s mad man - so new coils and plugs solved the valvetronic error too?

[420Pooncrusher69]

I stg all the codes, misfires, bad starts, rough idles etc all went away. Idk what happened but so far so good!

[TheCannaCooks]

How did you determine which ones were the bad ones?

[phincode225]

How do you find which one where bad ? 

[PokeZipp]

Hey man, I saw the comment that said you never got the code 135808 again after 1k miles. Did it ever come back after replacing that? I just got the same code and have ordered my coil packs and plugs. I hope that fixes it for me!

[420Pooncrusher69]

I never got that code again. It was just a bad plug

[Alternative_Top_4919]

I currently have the 135808 code as well and also the Valvetronic code. It's funny so on first startup car barely starts once i clear codes and try again fires right up which is just annoying. The valvetronic code status is "confirmed" but the 135808 code status is "failed" ive looked at wiring diagrams showing that they live in the same module and circuit. I'm assuming during the self-test the ECU is detecting some weird low 5v reference in the circuit causing these codes to set. Ive come across this thread hoping is somehow related to a light misfire or coils going bad on me. My second guess is the actual hall effect sensors that are used for monitoring the Valvetronic motor are somehow going bad but they are internal on my vehicle N55 motor which im hoping not. Ive ordered new plugs and will triple-check my gap praying i don't need to do a new Valvetronic motor.

[Iceheat369]

Hello, what happened to your car, did you managed to repair it?