x5 35d Engine Code P0238
 

Hi everyone, I have searched and read numerous posts about various issues related to this Engine Trouble Code and other various carbon build up / erg / manifold swirl valves, etc. and would appreciate any direction from the community possible. The language between realoem and terminology people is very confusing at times. Here is the problem:

Engine trouble light on with P0238 - Turbocharger / Supercharger Boost Sensor 'A' Circuit High

Listed Possible Causes (according to engine-codes.com)
- boost pressure sensor harness open or shorted
- boost pressure sensor circuit poor electrical connection
- faulty boost pressure sensor
- faulty turbo/super charger
- engine over temperature
-ignition misfire exceeds calibrated threshold
- faulty knock sensor (KS)

What I have done so far ...

Cleaned part# 13627792260 which is termed on realoem "fuel injection system - pressure sensor. I could not find "boost pressure sensor" terminology and other threads pointed to this item located on the driver side of intake manifold as a possible issue. When I took it out to clean it was clogged with carbon. I cleaned it with MAF sensor cleaner and reinstalled. I do not know how to test this sensor? How would I test to see if the carbon clog destroyed this one?

Next I cleaned the MAF sensor on the cold air intake.

If anyone can give me detail about how to eliminate the possible causes to ultimately identify the issue above one by one in a clear way I would greatly appreciate the advice.

Currently, I clear the code and it goes away until we shut off and re-start the car and then it appears again.

Thank you all in advance for any help!

1mGator

I am not an expert but would suggest you to replace it.They are prone to go bad.If you have BMW diagnostic software then there is a test plan which compares the pressure readings from this Map sensor with the readings from DPF sensor readings and checks for any discrepancy.
If you don't have any diagnostic software then your best bet would be to replace that sensor.

During my chase of some codes i replaced this sensor on mine and it wasnt it so i have a used one if you are interested. PM me Its just sitting in my garage

The only thing I've found to clean soot off of the MAP is throttle body cleaner which contains acetone.

I've been cleaning the MAP this way you every oil change for some time now.

Sent from my Nexus 7 using Tapatalk

My sensor also went bad. I cleaned it out by pouring some rubbing alcohol down the hole shown in the photo above. I then scraped out a ton of black goo with a small screwdriver. The X5 ran much better but was not perfect until I replaced it. I started this process monitoring manifold pressure with Torque for Android. I bet you are going to see some incorrect boost levels.

The part is $70. Just buy it. At some point the hassle isnt worth it.

Thank you all for your responses ... does anyone have any other information on anything other than the "boost pressure sensor"?

Until you monitor what your sensor sees, it is tough to help. In my case the sensor was reporting that the boost pressure was fluctuating between 15 and 20 psi several times per second which is unusual and not probable. My guess for you is the sensor is reporting higher than actual boost. What are you scanning codes with?

I have a COBB Accessport to use for scanning and monitoring. I am going to order a new sensor and keep my fingers crossed. Thanks!

Thank you all for your advice and help .... ordered "fuel injection system pressure sensor - #13627792260) and installed and cleared codes and good to go ... what a relief!