code P0234

[mikewarner]

Been having my 05 SuperDuty going into Limp Home Mode when pulling a load. Took it to a well respected diesel mechanic and he showed me where the differences in my water and oil temps were to much. He did a EGR delete, coolant flush and a new oil cooler. He also recommended i get something to monitor everything, so I purchased an Edge Evolution CS. Today, while pulling a small load up and extended grade the truck went into Limp Home Mode again... My edge showed the code P0234 which I've learned is Turbo Overboost. My ECT was about 185 deg and my EOT was 193 dwg. Is this a problem with my turbo?

I read on another forum about someone having this same problem and his Ford Dealer said it was caused by TSB 11-5-17 (whatever that is) They reprogrammed the PCM and he was fine. Have any of you heard of this before?

Thanks for any help.

[mikewarner]

Here are some numbers read from my CS as I was towing my 5er. The truck went into Limp Home Mode (showing code P0234) as I was pulling a fairly steep, extended grade at about 55mph. Outside temp was about 70deg......ECT-202, EOT-212, Turbo PSI 28

I turned off the truck which made the limp home mode go away and turned around and pulled the same hill again. This time I kept the speed down to about 45 with around 20 PSI of boost. She climbed the hill without going into Limp Home Mode.

Any thoughts??

[2 stroker]

Your deltas are OK mine have been as high as ECT 218* EOT 228* pulling 14,000lb 5er up a 7% grade 6 miles long in 90* weather so that part is good the PO234 is an overboost condition think you need to pull the turbo and clean 4C4Z-9V424-AA Turbo cleaning kit Max boost is 28lbs when i hit that i back out of it some.
DTS Articles - Turbocharger Reconditioning
2 stroker

[ephatfield]

I had this same problem last year and the dealership had to clean the turbo and have had no problem since.