Need help with p0238
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Stew
Sedans Rule!
Try this: Go to Engine Diagnostics -> Airflow and change the Overboost/Underboost to disable. I know it doesn't say P0238 in the description when you hover your mouse over that item but I reached out to a member whom I respect asking for help with this very issue and he instructed me to change this.
Now, report back and let me know if it resolves it for you because I have not yet updated my tune I'm embarrassed to admit. I keep clearing it with the ultragauge. A tip with the ultragauge - you can clear codes and limp mode on the fly, no need to pull over or restart, just be careful!
Now, report back and let me know if it resolves it for you because I have not yet updated my tune I'm embarrassed to admit. I keep clearing it with the ultragauge. A tip with the ultragauge - you can clear codes and limp mode on the fly, no need to pull over or restart, just be careful!
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I'll try it this evening if the weather is decent. My wife has the car at work right now.
Once I get that part down, I'm gonna put a wideband on it and see if I can get it running right.
My previous tune was getting almost 36mpg on interstate running 78.
On a side note, have you downloaded and used the new HPTuners yet? Get ready to set everything back up again!
Once I get that part down, I'm gonna put a wideband on it and see if I can get it running right.
My previous tune was getting almost 36mpg on interstate running 78.
On a side note, have you downloaded and used the new HPTuners yet? Get ready to set everything back up again!
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Didn't work ....
I did fix it but it was my last resort.
Under engine diag > dtcs > p0238 > no error reported
Hasn't tripped yet. I would have rathered fixed it than disable the DTC ... But it doesn't trip now. Now I need to get the throttle blade from closing under WOT.
Already got the MAF dialed in. VE table will need a little work. Then wideband.
Thanks for the suggestion BTW.
I did fix it but it was my last resort.
Under engine diag > dtcs > p0238 > no error reported
Hasn't tripped yet. I would have rathered fixed it than disable the DTC ... But it doesn't trip now. Now I need to get the throttle blade from closing under WOT.
Already got the MAF dialed in. VE table will need a little work. Then wideband.
Thanks for the suggestion BTW.
Negative.
Clarification for parameters in setting the P0238:
The ECM detects that the boost pressure sensor voltage is greater than 4.7 V for greater than 5 s.
And what happens when it's set:
The ECM will disable boost control and limit the system to mechanical boost only, resulting in a substantial decrease in engine power.
I don't know the voltage translation into kpa of that sensor, but from my experience it should be around 240kpa.
p0238 isn't normally for the wastegate actuator.
Clarification for parameters in setting the P0238:
The ECM detects that the boost pressure sensor voltage is greater than 4.7 V for greater than 5 s.
And what happens when it's set:
The ECM will disable boost control and limit the system to mechanical boost only, resulting in a substantial decrease in engine power.
I don't know the voltage translation into kpa of that sensor, but from my experience it should be around 240kpa.
p0238 isn't normally for the wastegate actuator.
Some interesting info relative to the subject ...
It *is* a 3 bar sensor, however max reading should only be around 269 kpa. I have seen that sensor max out in some of my logs.
From reading some tech documents, it looks like it was never intended for these things to see more than 220kpa on a regular basis. There things that suggest max being at 240kpa, but nothing saying it's limited.
For what it's worth, 240 kpa is 34.8 psi, MINUS the barometer (assumed to be between 60 and 120) reading. I'm pretty sure the barometer reading will vary by altitude and weather.
It *is* a 3 bar sensor, however max reading should only be around 269 kpa. I have seen that sensor max out in some of my logs.
From reading some tech documents, it looks like it was never intended for these things to see more than 220kpa on a regular basis. There things that suggest max being at 240kpa, but nothing saying it's limited.
For what it's worth, 240 kpa is 34.8 psi, MINUS the barometer (assumed to be between 60 and 120) reading. I'm pretty sure the barometer reading will vary by altitude and weather.
nickalltogether
New member
You are correct about barometric offset. You would of course want to tune for worst case scenario.
Standard temperature and pressure is 101.325kpa. So deduct that from your reading. My default max boost table has 255kpa in it. That's ~22.2 psig. A 3 bar should be good to 29psig, right? Even maxing out at 269kpa you should be able to reach 24psig. That has to be past the point of diminishing returns, at least for the stock turbo. Are you logging sensor voltage?
There is a driver demand table for reduced power mode. Will duplicating your standard driver demand table to this table work around the reduced power mode? You're already not reporting the error DTC's so maybe this will help.
I'm not looking at my tune ATM, just going off memory.
Standard temperature and pressure is 101.325kpa. So deduct that from your reading. My default max boost table has 255kpa in it. That's ~22.2 psig. A 3 bar should be good to 29psig, right? Even maxing out at 269kpa you should be able to reach 24psig. That has to be past the point of diminishing returns, at least for the stock turbo. Are you logging sensor voltage?
There is a driver demand table for reduced power mode. Will duplicating your standard driver demand table to this table work around the reduced power mode? You're already not reporting the error DTC's so maybe this will help.
I'm not looking at my tune ATM, just going off memory.
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Stew
Sedans Rule!
I probably won't be able to test it until this weekend, but I was thinking and I swear I had tried changing that without success.
nickalltogether
New member
Looked at my tune. I'd consider upping the reduced power mode torque management to match that of your main tune and doing the same with reduced power driver demand.
It's a bit of a shot in the dark because I'm not boosting to that level yet, but I will be up there before too much longer.
It's a bit of a shot in the dark because I'm not boosting to that level yet, but I will be up there before too much longer.
Naah. I'd leave your reduced engine power stock. That table is used for other errors too.
Stew if I had to guess you changed it to no mil. When changed to no error it doesn't even acknowledge the code exists anymore. It will never throw that code. Ever. There are codes in there already set to no mil. That just means it sets the code and stays in history for diagnosis at a later time.
I was reading tech docs when I was posting that. I didnt want to quote them but that's where it was coming from.
Stew if I had to guess you changed it to no mil. When changed to no error it doesn't even acknowledge the code exists anymore. It will never throw that code. Ever. There are codes in there already set to no mil. That just means it sets the code and stays in history for diagnosis at a later time.
I was reading tech docs when I was posting that. I didnt want to quote them but that's where it was coming from.
Stew
Sedans Rule!
It was a while ago, but I swear I had... having said that, I don't recall if I left the SES checkbox checked or not. Flyer, how do you have the SES checkbox?
Stew
Sedans Rule!
Did a little research and maybe I didn't uncheck the SES box when I set that to No Error Reported before.
What it sounds like is if you set to No Error Reported but still have the box checked, it will indeed still trigger the error and put you in limp mode just not give you a CEL or DTC.
If you uncheck the SES box the ECM pretends P0238 doesn't exist. The ECM will be like "What? I didn't see a P0238, that's my story and I'm sticking to it!"
Alright, I'm going out to flash the ECM, I'll report back later this week with my findings.