Code 120308 Low pressure and Transmission malfunction light turns on

ASHOK SAINI

MEMBER
2013 BMW X3
2.0L
4 CYL
4WD
AUTOMATIC
160,000 MILES

I need your help. A Code 120308 Low pressure code comes on Transmission malfunction light comes if I drive over 80 kms/hour, lower speed car is running smooth at 40-60 kms/hour. Vacuum pump, boost solenoid switch replaced. Could a diverter valve replacement be required? Before I had lean fuel code which was corrected by installing new turbo intake pipe.
Pl. Suggest.
Thanks,
Ashok Toronto

Car listed above has turbo.

4 Replies

KEN L

MASTER CERTIFIED MECHANIC
47,619 POSTS

I low pressure code can be caused by a clogged transmission filter which is where I would start. Drop the pan to do the service. This generic guide can help us with specific instructions below for your car. Clear the codes once complete.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

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Thursday, June 9th, 2022 AT 7:06 PM

ASHOK SAINI

MEMBER
32 POSTS

Hi,

I still have the problem 120308 Charge air pressure control, plausibility pressure too low. It's perhaps due to just 1 part or seal which needs replacement (very sure) code is permanent. I haven't tried your previous suggestion yet. Clogged transmission filter check. Code 120308 Low pressure code comes on Transmission malfunction light comes if I drive over 60-70 kms/hour, at lower speed car is running smooth. The vacuum pump, boost solenoid switch replaced are replaced. Since I replaced Turbo intake charge pipe that code (118001 Lean mixture code is eliminated). YouTube videos suggest diverter valve, spark plug change. There is no misfire, so I rule our change of plugs, but diverter valve I don't know. Please suggest what else I can do.

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Sunday, June 26th, 2022 AT 11:56 AM

KEN L

MASTER CERTIFIED MECHANIC
47,619 POSTS

We handle one problem at a time per thread. Please post your new question here, you must be logged in.

https://www.2carpros.com/questions/new

Please let us know what happens with the Code 120308 Low pressure, Cheers, Ken

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Monday, June 27th, 2022 AT 1:20 PM

ASHOK SAINI

MEMBER
32 POSTS
2013 BMW X3
2.0L
4 CYL
4WD
AUTOMATIC
160,000 MILES

I have the problem 120308 Charge air pressure control, plausibility pressure too low. Low pressure code comes on Transmission malfunction light comes if I drive over 60-70 kms/hour, at lower speed car is running smooth. The vacuum pump, boost solenoid switch replaced are replaced. Since I replaced Turbo intake charge pipe that code (118001 Lean mixture code is eliminated). Please suggest what else I can do.

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Tuesday, June 28th, 2022 AT 10:16 AM (Merged)