Hi All

I was hoping for a little guidance here. So, I have a 2005 CRD, 165K miles, GDE eco tune. When I accelerate uphill onto the freeway I'm getting an overboost code p0234. I replaced the MAP and cleaned the air filter with no change. I inspected the hoses and they look ok, but I haven't pulled any of them. I've been reading a lot of posts on this issue and it seems like if the p0234 is not solved by the MAP replacement then it can be a little murky to track down. I'm not the world's greatest mechanic, so at this point I'll probably need to pay for diagnostics. I've been driving the jeep for the last 100k miles and I've barely done anything to it besides oil changes (never changed any hoses, vacuum lines, ets.). I plan on driving this rig until it finally completely explodes. So, if I'm planning on keeping it and I've never really replaced any of the old parts I was thinking maybe I should just replace all the likely culprits and see if this solves the problem. Hopefully, it's not the turbo! So, what is the list of parts that are likely related to my p0234? And what other parts should I be suspicious of after 100k of ownership? I'd like to be able to trust the jeep again for our long summer road trips. Or am I thinking about this wrong and should I just bring it an independent diesel shop and have them do diagnosis?

thanks
Duncan

Start cheap...

Remove the sensor on the SIDE of the airbox. Blow it off with compressed air and maybe some electronics cleaner. Inspect the electrical connector for damage, bent pins, etc. Let the sensor dry and reinstall it firmly.

Fully remove and inspect each intake related hose, airbox-to-turbo, turbo-to-IC, IC-to-intake. Clean and reinstall AFTER the next step. Replace any that have issues.

While the airbox hose is off, reach into the turbo inlet and wiggle the turbine shaft. It shouldn't move much side to side, no more than about 1/64".

Check the entire vacuum hose leading to the turbo actuator for potential leaks. Any rub marks, cuts or holes are a problem. If you find any problems, replace the hose.

Remove the small air filter from the bottom of the solenoid on the passenger side and make sure you can blow through it. Replace it if you cant.

If everything checks out there, then move on to these...

Start the motor and listen to the solenoids. They should not be buzzing or making any discernible noise. Replace them if they are.

Pop the vacuum hose off the turbo actuator and watch the rod going to the turbo. It should move about 1/2" in a fairly quick manner. If it doesn't move very far or moves slowly, your vanes are stuck. You may have to rent or borrow a vacuum pump to work the turbo vanes back and forth and free them up. Some spirited driving after loosening them should help free them up more.

If nothing changes after doing all that, post back here and we'll move on to the next thing!

_________________
2006 Limited CRD: Frankenlift II, Fumoto Drain Plug, DIY Stage 1 Tune, In-Tank Lift Pump

Replace both vacuum solenoids.
They are available from IDparts.com

_________________
U.S. Army Retired

Thanks, you guys! This is exactly what I needed. A clear defined workflow is what I was missing. Since I'm pretty sure all these hoses are original I think I'll treat myself to some Samcos for peace of mind. I'll jump on this project early next week and report back. I may just go ahead and replace the solenoids, as they look pretty cheap at IDParts.

thanks!
Duncan