P0234 Overboost

Justin Technician California Posted   Latest  
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Driveability
2015 Dodge Dart Aero 1.4L (H EAF) 6-spd (DA1-C635)
P0234 — Turbocharger/Supercharger "A" Overboost Condition

This vehicle has had a turbo and wastegate solenoid . I have tested boost pressure with the a manual gauge . The boost sensors are showing a matching reading . I will say that intake map sensor reads lower at times when overboost occurs and etc closes . Any ideas ???

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Steven Mechanic
Washington
Steven
 

Does the scan tool have desired and actual boost data? If so, can you graph the data and post it?

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Charles Technician
California
Charles
 

So if you take off the metal shield on top of the turbo and look at the waste gate arm, are there any witness marks on the nut that holds that arms length adjustment in place? If so it has probably been adjusted from its factory setting for some reason. Getting it to the correct adjustment will be tricky if not impossible. Where did they source the turbo from? If you get an oem turbo it comes…

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Justin Technician
California
Justin
 

It’s oem and I am a dealer tech . It opens at 6psi and fully opens at 20 psi . No specs for any of it . i Will post graph of data

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Charles Technician
California
Charles
 

Being over 4 PSI from what the PCM is expecting to see is all it takes to trip that pressure fault. So a couple other things I thought of to check. Intake and coolant temp sensors are reading the same when cold? Have you swapped the MAP sensor with a known good one? And have you checked to see if you have an exhaust restriction? That one is kind of hard to do with the multiair system and may…

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Robert Technician
Michigan
Robert
   

Well Chuck does have a point usually that is an actuator rod tweak DTC no more than 1 turn per adjustment increments trial & error test drive for DTC we used to have to adjust on some Cobalt's/HHR's….. Wastegate Actuator Adjustment in SI if applicable but; To reduce boost make shaft longer for P0234////…. P0299 is underboost … The actuator 6-20 NO specs really should begin moving 3-9 psi…

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Caleb Diagnostician
Indiana
Caleb
 

Like Steven said need to graph actual and desired boost along with wastegate solenoid command PID. Until we have that data not sure how we can help. Does that wastegate work or is it stuck in the full boost position. Should be easy to do in the bay. Is this a normally open wastegate or closed??

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Justin Technician
California
Justin
 

This is a normally closed waste gate that relies on the solenoid to deliver pulse width modulated air psi to open waste gate via servo spring style actuator . I monitored PID and all it shows is wastegate active so I road tested with pico and my solenoid was being triggered from about 5 percent to around 80 percent when overboosting . I will say I put a fuel pressure gauge in parallel with…

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Justin Technician
California
Justin
 

Here is some more info . I took a like vehicle and compared data . I am about ready to put a go pro camera on turbo actuator rod on wot pass !!

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Marvin Mechanic
Mississippi
Marvin
 

Does this vehicle have back prsuure sensor like a diesel

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Marvin Mechanic
Mississippi
Marvin
 

What do you mean etc closes

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Andrew Owner/Technician
New Jersey
Andrew
 

Just had a 2011 Buick Regal setting a p0234 that was stumping me. found the wastegate actuator was not holding vacuum causing the overboost condition.

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Justin Technician
California
Justin
 

Any ideas after looking at pics ?

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Caleb Diagnostician
Indiana
Caleb
 

Justin, shoot me an email …

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Justin Technician
California
Justin
   

The pcm replacement fixed this one . I hate to blame anyone because it’s my job to resolve the hard ones but this would have been easier if I could have added a line of data in pcm for boost solenoid duty cycle . . . Instead of OEM only giving On or Off for a freaking duty cycled component !! Then I could have compared using picoscope . Luckily I had one 3 months later to compare boost solenoid…

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