A week and a half ago...less than ten hours before our 16 hour road trip to the Outter Banks my check engine light came on. I called On-Star they did a check and told me I needed to get the truck to a dealership as soon a s possible. The truck was running fine.....in fact it came on right when I started it. OK, now I am freaking out.....I call my NAPA bud and talked with him for a while as we tried to find a 'open late' dealership, no luck. I unpluged the Edge...which I was told will drop the code. So I called On-Star back to get the code which they still had. It was P0234....after three starts the light went out. I then pluged the Edge back in. We left the next morning and had the truck running for 13hours no light. Had to drive on the beach for 10miles no light. Drove home no light. The last hour it came on. It was the same code P0234.


While I was away my friend at the dealership called me back and told me it was a Over Boost for more than 10 seconds. Ok, but!!! the first time was right after I started the engine and was driving in a 25mph and the second time was on the highway but I was in traffic doing 50mph. I am going to the dealership today but I still wanted to get this out and see what the members might think.


Thanks for reading.

overboost code as noted, does it set with the edge off? Gotta start there...


If baro sensor data is screwy or boost sensor data messed up.. likely they wont find anything and just clear it.

http://www.dieselplace.com/forum/smileys/Ermm.gif You need to take out the chip and see what happens. Or if you are going to run it with the chip in, you need a turbo press gauge and a pyrometer. If you can't tell a difference in the way your truck runs,(when the light comes on) then the problem could be instrumentation.http://www.dieselplace.com/forum/smileys/Rock On.gif

I have the Attitude and everything was fine with the boost and EGT. Both times I had the Juice on 3. The first time was right when I started it up with the egine warm, the second was only doing 50mph in traffic....the engine did seem to run fine.....there might have been a bump down in RPMs...but I am not certain like I said I was in traffic.


We did drive though the Great Smoky Mtns....about 3,00msl the way out and spent the night in Asheville without problems. As a side note

It only takes 5psi for 12 seconds to set the code. I thought the Attitude would not allow that code to be set. If not, then it would be easy to set it just after startup. My DMax always required a little more boost to get moving when cold. Also, it must happen on two consecutive ignition cycles to set the code. It will reset itself after 3 ignition cycles without breaking the 5psi/12sec rule.

Amric, so are you saying this is a Juice thing or a Duramax thing?


I am not to sure what you mean when you say 5psi for 12 seconds....is this 5psi over the factory max or just 5psi.


I am really confused about the whole thing.


Thanks for your help

It is a Duramax thing that I thought the Edge intercepted before the the ECM could through the code. Here is a writeup
DTC P0234 Federal RPO FE9, NG1
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Circuit Description (http://service.gm.com/servlets/BlobShtml?ShtmlFile=865735&amp;psdid=437&amp;evc=sm#ss1-865735)
The boost sensor responds to pressure changes in the intake manifold. This pressure is created by the turbocharger and changes with accelerator pedal position (APP) and engine speed. The engine control module (ECM) uses this information to assist in diagnosis of the barometric pressure (BARO) sensor and to provide engine overboost protection. The boost sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The ECM supplies 5 volts to the boost sensor on a 5-volt reference circuit, and provides a ground on a low reference circuit. The boost sensor provides a voltage signal to the ECM on a signal circuit relative to the pressure changes. The ECM monitors the boost sensor signal for voltage outside of the normal range. The ECM calculates a predicted value for the boost sensor. The ECM then compares the predicted value to the actual signal. This DTC will set if the boost sensor signal is above the predicted range.
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[url="http://service.gm.com/servlets/BlobShtml?ShtmlFile=865735&amp;psdid=437&amp;evc=sm#ss2-865735"]Conditions for Running the DTC (http://service.gm.com/servlets/BlobShtml?ShtmlFile=865735&amp;psdid=437&amp;evc=sm#ss2-865735)
<UL =square>
<LI class=MsoNormal style="MARGIN: 0in 0in 0pt; COLOR: black; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto; mso-list: l1 level1 lfo1; tab-stops: list .5in">DTC P0238 is not set. </LI>
<LI class=MsoNormal style="MARGIN: 0in 0in 0pt; COLOR: black; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto; mso-list: l1 level1 lfo1; tab-stops: list .5in">The engine speed is less than 2,700 RPM. </LI>
<LI class=MsoNormal style="MARGIN: 0in 0in 0pt; COLOR: black; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto; mso-list: l1 level1 lfo1; tab-stops: list .5in">The fuel quantity is less than 70 mm³. </LI>
<LI class=MsoNormal style

Wow, thanks for the information. It looks like this is a Intermittent problem. I had the AFE on the truck since the day after Christmas so I do not think that it is the problem. Next time it happens will not unplug the Edge and have my friend look at the snap shot.


Thanks for the info again.