[jwtw]

So I replaced my valve cover and gasket last week (no leaks!! F* YAH!!).

BUT, when I was test driving the car I got the Drivetrain Malfunction error message. Sigh.

Car is supposed to go in "limp" mode. But it runs fine. No weird noises or power loss issues. I don't hammer it when it pops the code. But as far as I can tell it runs fine.

As soon as I turn the car off the code clears. When I go back out for a drive the code will pop after about 10 minutes or so. No rhyme or reason when the code pops. Cruising speeds or hammering it, it'll pop doing both.

I did replace the pressure converter and hose because that's the only thing that I removed from the car when I did the VCG. At least the only thing that makes sense as far as the code is concerned.

Does anyone have any thoughts on what I should look for? Don't really want to replace random parts. I find it strange that I have this issue after I replace the VC. Ugh.

Anyway thanks for any and all help!!

Enter fault code: 120308
Possible cause of fault:
- Boost pressure sensor defective
- Pressure converter wastegate valve + hose / Replaced 8.8.2020
- Wastegate valve defective (stuck open)

[Billfitz]

When you get a code google it along with 'BMW'. You'll usually get a large number of results, like this one: https://static.nhtsa.gov/odi/tsbs/20...41407-5981.pdf

[F15_SGM]

Originally Posted by jwtw

So I replaced my valve cover and gasket last week (no leaks!! F* YAH!!).

BUT, when I was test driving the car I got the Drivetrain Malfunction error message. Sigh.

Car is supposed to go in "limp" mode. But it runs fine. No weird noises or power loss issues. I don't hammer it when it pops the code. But as far as I can tell it runs fine.

As soon as I turn the car off the code clears. When I go back out for a drive the code will pop after about 10 minutes or so. No rhyme or reason when the code pops. Cruising speeds or hammering it, it'll pop doing both.

I did replace the pressure converter and hose because that's the only thing that I removed from the car when I did the VCG. At least the only thing that makes sense as far as the code is concerned.

Does anyone have any thoughts on what I should look for? Don't really want to replace random parts. I find it strange that I have this issue after I replace the VC. Ugh.

Anyway thanks for any and all help!!

Enter fault code: 120308
Possible cause of fault:
- Boost pressure sensor defective
- Pressure converter wastegate valve + hose / Replaced 8.8.2020
- Wastegate valve defective (stuck open)

Same code what was the issue?