2008 550i Throttle Body Operation

[Paulh634]

First off I apologize if this is not the right location for this question.

I have a 2008 550i that is throwing the codes P120 and P1637 and continually going into limp mode.

Removed the duct connecting to the throttle body, so I could see what the throttle body was doing. When the car is off the throttle body is closed, when starting the car it does not cycle or move, when engine is revved it will open 1/16'' at max.

From my understanding the throttle body should cycle when the car is started and then remain in the full open position, correct?

Reading other forums/posts it looks like most people have replaced the throttle body and wiring harness. Can someone tell me what the voltages should be going to each of the pins on the throttle body connector or is there another way to test the wiring short of replacing the harness. Throttle body was just replaced.

[White94RX]

You are correct about the operation of the throttle. It should be open fully with the engine running.

Sorry I can't answer your other questions.

[Paulh634]

You are correct about the operation of the throttle. It should be open fully with the engine running.

Sorry I can't answer your other questions.

Well thank you for that. I purchased a scanner from xcar360.
https://www.xcar360.com/bmw-icom-a2-...k-version.html

Hopefully with that I'll be able to get inpa functioning and will be able to gather something that steers me in the right direction.

Apparently the throttle body was just replaced before the issue was passed on to me, leads me to believe it is either the wiring or the accelerator pedal, but I'm not finding much in the way of testing before replacement.

[solingen]

That looks like a good unit, it should get you pointed.

Sent from my ASUS_Z00LD using Tapatalk

[White94RX]

If I remember, at some point there was a service bulletin that said to replace the wiring to the throttle body...

Found it. SI B12 26 09. Maybe you can google it and pull it up. I'm not sure if I am allowed to copy and paste BMW service bulletins. Here's the part number of the repair harness: 12 51 7 602 973