Check engine light on and code120308

Tiny
CHRIS THOMAS2
  • MEMBER
  • 2012 BMW 528
  • TURBO
  • AUTOMATIC
  • 186,000 MILES
I don’t know what’s wrong with my car. I don’t have a check engine light on it though after I get the drivetrain malfunction.
Wednesday, June 29th, 2022 AT 7:05 PM

1 Reply

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,968 POSTS
The code #120308 boost pressure control, plausibility: pressure too low, I would start by checking the turbo tubes and boots to make sure they are in good shape with no leaks. If okay I would check the turbo main shaft endplay, if excessive I would replace the turbo. Here is a guide to help you see what I am talking about. Also, I have left instructions on how to change out the turbo in the diagrams below.

https://www.2carpros.com/articles/how-turbo-chargers-work

Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.
Was this
answer
helpful?
Yes
No
Thursday, June 30th, 2022 AT 8:44 PM

Please login or register to post a reply.

Sponsored links