Turbo Overboost Code with new calibration

[fordtech03]

I've seen two trucks in the past week that set the P0234. The MAP and EBP sensors were within spec and working as the should. Basically you have to go and run these hard till you get the EOT up around 205 and it will overboost under a hard load, typically uphill holding to the floor. ON both vehicles the VGT actuator tip was severely worn down off to the side of the tip, and the arm inside the turbo had a nice wear pattern in it. After disassembling the turbos the CHRA and unison ring had to me it seems about the normal amount of carbon and rust(mild) that we typicaly see on these, the vanes moved freely with no apparent sticking. Truck #1 got a new turbo and actuator and road tested just fine. Truck #2 had both on order for tomorrow. Is anybody else seeing these comeing in after the latest calibration? I was getting over 29psi under load at 80mph.

[mchan68]

I've seen two trucks that have come in with this particular DTC set in CM. On both trucks, EBP, MAP and BARO were well within specs. Of course, "around the block" road testing of these units failed to reveal anything that was not right, given that both of these particular trucks came from owners who complained only of loosing power while driving on the highway pulling a trailer under heavy load. Unfortunately, I have no means of being able to road test these vehicles under similar conditions to be able to attempt to re-create the concern. But judging from the number of posts I've been reading lately about this very complaint is leaving me wondering if the most current calibration may just be a tad bit too sensitive. Just my

[mchan68]

Furthermore, I'm still not to clear on how the most current calibration works for '03/'04 model year trucks, since not much mention is made of them, it seems.

[Aaron]

Shh, that's a SECRET!

[fordtech03]

Both of those trucks are used for towing, and I live in a hilly area so the owners are definitely a bit upset when they go to forced limited power pulling a loaded tralier up a mountain. I watched the MGP plot, it was holding over 29 psi before it turned the wrench light on. Thing is, is I had to really lay into it to get it to do it, it's the best we can come up with to "somewhat" duplicate the conditions they are driven vice towing a loaded horse trailer while we are testing....lol.....this is basically the same way we would check for bad head gaskets, we have one mountain in particular that makes them puke everytime if they are bad.

[Fordracer]

I had one that was pulling a big fifth wheel and it had the overboost code and it was over 29 psi. The unison ring was stuck on the CHRA.

I also have had two trucks come in with new code P012F - Engine Coolant Temperature/ Engine Oil Temperature Correlation. The pinpoint test AJ4 for this is hilarious.

 

 

Clear all the DTCs.

Cold soak the vehicle at ambient temperature for a minimum of 10 hours.

Ignition ON, engine OFF.

Access the PCM and monitor the ECT and EOT PIDs.

Access the PCM and monitor the RPM PID.

Access the PCM and monitor the MFDES PID.

Record the ECT and EOT sensor temperature values.

Drive the vehicle at an engine speed greater than 1,800 RPM and 15 mg/stroke MFDES for at least 15 minutes. Select the appropriate gear to achieve the operating conditions.

 

Does the ECT PID and EOT PID temperature values change by a minimum of 6°C (10°F) from when the ignition ON, engine OFF valves were recorded?

 

 

WTF!!! I can get the temp to change 10 degrees sitting in my stall. Why do they want you to go through all that to see if the temp changes 10 degrees?

[Aaron]

Yeah, especially since the "spec" is 15 degrees, this week.

[DieselD]

Ive been getting this too without being able to catch it. It reminds me of the good old 2003 6.0 release when everything was setting a MIL. soon after the programming was dumbed up a bit to prevent particular DTCs from setting a MIL. Seems we might be heading back in that direction.

 

I did have one with an overboost that the actual unison ring stuck full bore on once it got hot. 115* ambient temp with me hammering on the truck for about 10miles