On May 25, I was towing a 31 foot 5th wheel near Portland, OR. The engine wrench symbol came on along with reduced engine power message.We limped into Portland to Gresham Ford for repairs. They immediately did a DTC check and the code P0234 was displayed.

The day before, on 24 May, Ford issued a TSB 11-5-17 concerning DTC Code P0234. Any Superduty that had the Ford Reprogram 11B23 PMC update between 2/23/2011 and 5/18/2011 may exhibit DTC P0234 overboost under heavy load, towing or while climbing an extended grade. I was doing all of the above when the enginse wrench came on.

Gresham Ford reprogrammed the PCM to the latest calibration that corrects the
DTC P0234. The TSB outlines the dealership doing an Oasis check to verify the last program date. If it is between 2/23/2011 to 5/18/2011 the dealer will reprogran to the latest calibration.to prevent the engine wrench display and reduced engine power.

My hat is off to Gresham Ford for resolving the problem within 24 hours after Ford issued the correction TSB. The service department was most helpful in getting my Super Duty and 5th wheel back on the road.

 

I called my trusty SA and he said they will only reprogram if the wrench is on. They will not update if it is not on.

 

When you threw the code how much boost were you getting at the time?

I routinely will get 38-40 psi when pulling hard.

 

I rechecked the TSB 11-5-17 and it does state the issue is the DTC P0234 over boost under heavy load, towing or while climbing an extended grade. I guess it will require the wrench and reduced power message before Ford will reflash with the corrected reprogram. I didn't notice the boost reading at the time of occurrence.

I did a towing trip to Sacramento from BC in March after the reflash and had no problems. When it occurred during a towing trip in OR in late May it was very stressful to have reduced engine power with a 5th wheel trailer for an hour on I -84 and in Portland City traffic. When one adds in the stress of waiting in a dealership for an hour waiting for the diagnose and fix, owning a Chev truck was looking good to me. I did not appreciate the event at all and feel Ford should fix all of the re flashed trucks done between 23 February and 18 May. The fault is in the reflash, pure and simple, not mine.

 

Took my 2010 6.4 into tirlakes motors in Branson today. Since getting the 11b23 flash April 3rd 2011 I have only towed twice in mountainous areas and both times experienced overboost, stuttering and hesitating up long grades.
No CEL's, wrenches on dash or limp modes conditions noted but dealer found the P0234 codes in the history and using the info from hear about TSB 11-5-17 reflashed my truck under warranty and after even without trailer on hitch i can tell truck is running better than it has since the dreaded 11b23 was installed.
Thanks TriLakes Motors, hopefully it pulls grades strong again Saturday when I hit the road again.

 

Well after towing over 800 miles home the truck ran perfectly once again. It regen'd at 480 miles after the reflash on the way home and did not regen again before we finsihed towing the rest of the 800 miles home,
It was much more responsive both towing and bob-tailing and I never experience any more stumbling pulling grades with the trailer onboard. towing mileage range from 8.5 upto 11mpg depending on speed and wind and direction travelled

Overall very happy with truck once again

However:
The "Cleaning Exhaust Filter" message now sttays on the dash display all the time when it is in cleaning mode unless you press the "reset" button to dismiss the message.

I like it that way?

 

I had the code show up in the history as well. Mine was already updated per the TSB and then it showed up.

My high pressure turbo was 3.67 psi out of spec. So they changed it.

My symptoms were a decrease in mpg's and regens closer together so I took it in for that and they found the code.

 

Mine was staying on about half the time following the first (11b23) flash. I did not experience any problems and therefore did not have the follow up flash. I don't think it's supposed to stay on but I decided since it was running good otherwise i'd ignor it. I don't know what it's doing now as it's laying in the attic of my shop.

 

If you build a good relationship with your dealer they will reprogram at any time! At least mine will for me.