Ongoing P0299 underboost problems

mattbucher · **Posted:** Thu Jun 29, 2017 11:35 pm

I hope my signature and profile update is helpful...

Thank you...

I just got down to where I put in the intake, exhaust, and flywheel pins tonight...

Cleaning intercooler with degreaser...

Plan to get into timing belt, water pump, thermostat, new fan clutch tomorrow and this weekend...

Also...just to clarify...the diesel mechanic did a boost pressure test and did not find any leaks...

Next he checked all vacuum lines (even traced into the dash on the inside...no leaks).

Then he put a pressure gauge between vacuum modulator and turbo...

He found with underboost it was only showing 14in Hg (with vacuum gauge not boost pressure)...so he applied a manual vacuum to bypass the vacuum modulator and put it at 27 in Hg on the vacuum and it no longer gave an underboost code...trying to clarify with them if this was at idle like I first thought...does that change anything for your assessment?

Thanks...

mattbucher · **Posted:** Mon Jul 03, 2017 9:14 pm

Update...

This weekend I put on a new timing belt, timing idler pulleys, timing belt tensioner, water pump, thermostat, alternator, me serpentine belt, and cleaned and pressure tested my intercooler. No leaks in intercooler. It held 35 psi for over 2 hours without drop in pressure. I also had put in IAP sensor. Also check wiring to IAP sensor.

Still getting P0299. Feels sluggish when it kicks on? Maybe my imagination.

Any idea if new vacuum reservoir would be worth a try? At only $25 from IDOarts it would be by far the cheapest part I've replace (that didn't need replacing).

I'm gonna trace back all MAP sensor wiring tonight and I'll let you know if I find anything.

mattbucher · **Posted:** Mon Jul 03, 2017 9:15 pm

Should say new serpentine belt...not me serpentine belt.

GordnadoCRD · **Posted:** Mon Jul 03, 2017 9:48 pm

mattbucher wrote:

Any idea if new vacuum reservoir would be worth a try? At only $25 from IDOarts it would be by far the cheapest part I've replace (that didn't need replacing).

Well, that's the only thing left in the turbo vacuum control circuit. It's definitely worth a try. I like to know for sure what's going on first, but, (baseball analogy) sometimes you just gotta swing, cause you'll never hit if you don't.

mattbucher · **Posted:** Mon Jul 03, 2017 11:03 pm

Just traced wiring from IAP sensor, Mass Airflow Sensor, and MAP sensor from plug up to main wiring harness. Even opened up plastic casing on top of engine to check sensor wiring as it enters the mass of wires in the wiring harness. No luck. Cannot find anything that is damaged in any way.

Guess I'll drop another $25 and see...but have to admit I'm starting to wonder if it will ever be fixed.

After that I guess go to catalytic converter removal...???

Driving me crazy.

Happy 4ty of July.

Thanks.

mattbucher · **Posted:** Thu Jul 06, 2017 9:34 pm

Well...I can see my turbo vacuum actuator arm move up and down fully when I disconnect and reconnect vacuum to my turbo. Next I tried hooking vacuum straight to turbo to bypass vacuum solenoid and vacuum modulator...It ran wide open then bogged and blew some black smoke and put me in limp mode with only overboost code. Then I cleared it and tried removing the in line vacuum check valve thinking that may be the problem and back to underboost code? When I pull my vacuum line off the reservoir it hisses which I'm guessing is telling me it is holding some vacuum ? I should get my new vacuum reservoir and another vacuum solenoid tomorrow...then if that doesn't help I'm gonna cut off my cat converter and if that doesn't help...then where do I go from here???

GordnadoCRD · **Posted:** Thu Jul 06, 2017 10:12 pm

Let us know what you do and how the symptoms change.

Recommend if you are pulling the CAT converter, cut exhaust behind the woven flex section, eave enough behind to attach a 2.5" test pipe (about 3").
Cut behind the muffler, (also about 3"), and remove the whole section between the cuts (don't even bother to undo the coupler), and set aside the section between the cuts.
Either have a section made, or get a piece of 2 1/2" exhaust pipe about 1/8" to 1/4" longer than the section you removed (total), and use (2) 2 1/2" stainless steel band exhaust clamps to fasten it in place. If it works you will know without having to put out $100 for a new quality muffler before knowing.
If it's fixed the problem, and it's too loud, then you can put out the dough for whatever freeflowing muffler you wish.

mattbucher · **Posted:** Fri Jul 07, 2017 7:26 pm

Updates...

Yesterday I double checked my turbo and I can see the turbo actuator rod moving fully up and down when I disconnect and reconnect my vacuum line at idle. I tried taking out the vacuum line check valve to see if it was faulty...but it again gave me an underboost code running without check valve in place.

Next...I hooked the vacuum line directly into my turbo (bypassing the vacuum reservoir, solenoid, and vacuum modulator) and it ran wide open and then put in limp mode and gave me only the OVERBOOST code.

This morning I had the catalytic converter cut off, new flex pipe installed with straight pipe in place of catalytic converter and 2.5 in/out flowmax exhaust put on it...It sounds great but still getting underboost code?

I am going to put on a new vacuum reservoir tonight (came in the mail today from IDPARTS.COM) and I got another solenoid to see if it may be faulty...

But am starting to lose faith?

Just to summarize what has been done...
- New upgraded Sasquatch.com turbo
- New PCV valve
- New airbox Inlet Hose to turbo
- EGR Delete Kit from Sasquatch (Weeks Stage 1&2)
- New Intercooler Hoses (Mishimoto)
- Replaced TWO MAP sensors
- Traced all wiring from MAP and IAP sensors to main harness to check for short (all wiring intact)
- Replaced IAP Sensor
- New vacuum line from Vacuum solenoid to turbo
- New ETECNO 7V Glow Plugs
- Vacuum Modulator and filter replaced
- New Vacuum Solenoid
- New Mass Airflow Sensor

The diesel mechanic did a boost pressure test without leaks and also did a vacuum check and reports he checked all vacuum lines - even the one that goes in the firewall to the inside of the jeep - no leaks detected.

The turbo actuator is moving up and down on the turbo at idle when I pull off the vacuum hose from the solenoid and replace it.

Last weekend I replaced my timing belt and pulled my intercooler and cleaned it...and used the pressure test kit from Sasquatch.com to check for leaks. It held 35psi of pressure for 2 hours without a drop in pressure at all.

I also replaced my water pump, thermostat, fan clutch, and alternator (just to keep a spare alternator on hand given it is at 111,000 miles) and put on the Provent system to keep oil out of my intercooler and turbo hoses.

Where to go from here?

flash7210 · **Posted:** Fri Jul 07, 2017 8:42 pm

You have done everything right and all your test results indicate that the turbo is functioning normally.
I hope the vacuum pieces you ordered will get it back in order.
After everything you have done so far, there are only two things I can add.

1. You need a way to monitor actual boost from the turbo.
The easist way is with a Android phone/tablet + torquePro app + ELM327 OBD bluetooth adapter.
Or, install a mechanical boost gauge.

2. Contact SasquatchParts and ask about how they set the adjustment for the turbo vane actuator.
Somehow I missed the fact that you replaced the turbo.
Generally, we expect a new turbo to have its actuator adjustments to be properly set. But given what youve done so far, its the only thing left to do.

mattbucher · **Posted:** Fri Jul 07, 2017 8:58 pm

Thanks flash. I'll let you know how it goes. Probably won't get to working on it till tomorrow.

mattbucher · **Posted:** Tue Jul 11, 2017 9:44 pm

Update - Still not fixed...ongoing P0299

This weekend I put on the new vacuum reservoir and solenoid. I also traced all vacuum lines myself from the engine to brake master cylinder and went through all of the rubber vacuum hose connections between the hard lines and replaced ALL of the rubber vacuum sections. I also pulled all of the check valves - brake booster, HVAC unit behind glove box, and the one by the vacuum reservoir for the turbo and all check valves are functioning properly without leaks. I pulled my coolant reservoir and traced lines behind that and replaced rubber hose sections. I pulled my MAP sensor and used a wire brush from a dremel tool to very carefully clean inside the port where the map sensor sits on the engine (in case there was buildup around the sensor that was affecting the flow). At some point the MAP sensor was plugged in with the clip on the wiring facing down instead of on top. I was so so hopeful that was the issue...cleaned MAP with brake cleaner and put the connector on firmly with the connector clip facing upwards...put back together and blew out air filter and drove it for about 10 mins - still got P0299 in pending codes...but not confirmed...

Thought maybe I had a fix....kept clearing it from pending codes.

I drive about 20 miles to and from work...

Went for an hour drive today and it was back in confirmed codes.

Yesterday I went ahead and ordered the GDE ECO tune...given I thought I had my P0299 fixed...but now it is back on confirmed codes from my OBD II scanner...so I really don't know what to do.

I have a BlueDriver OBD scanner for my iPhone...

Any ideas if the TorquePro app will work with this or do I have to buy another scanner?

After I get the ability to monitor actual boost from the turbo...what am I supposed to look for with the Torque Pro app?

I guess at this point I'll move forward with the GDE ECO tune since I purchased it yesterday?

I am doing the scantool option from GDE instead of mail-in ECM...

I will email sasquatch.com tonight to see about how they set the adjustment for the turbo vane actuator.

Thanks.

GordnadoCRD · **Posted:** Wed Jul 12, 2017 1:00 am

Without being there to observe and test myself, You've done everything that I would check and try.

You are in hands much better equipped than mine, to solve your problem.

Good luck, and please let us know what you find. (I really really hope it's not the ecu)

mattbucher · **Posted:** Mon Jul 17, 2017 10:25 pm

I emailed Sasquatch about the turbo...Seth at Sasquatch was great and talked with their turbo builder...and had me send some pics of my actuator adjustment screw. He had the turbo manufacturer review them and they said to loosen the actuator adjustment nut 1/8 in and thread the bolt down on actuator to adjust...they said to do this in incrinents of 1/8 in and see if it fixed the underboost problem.

I purchased the GDE ECO tune when it seemed like the vacuum reservoir would work...so I went ahead and put on the ECO tune (after talking with Keith at GDE first)...figured I'd try the tune before starting to change turbo actuator adjustment screw...

So...I put on the GDE ECO tune and have driven it 5 days...start/stop driving and highway...and no more turbo underboost code. It is awesome!!!

Didn't change anything on turbo actuator.

Any ideas why it would fix it?

If it stays good I'm not adjusting anything on turbo.

I emailed Sasquatch and Keith at GDE today and they both said they don't know why it fixed the P0299...but as long as the code stays away I'm not messing with it!

Still have fuel filter and transmission filters to change but taking a break for a while.

I'll keep you posted but hope problems are solved for a while!

Thank you all very much for all of your time and help!
-matt

GordnadoCRD · **Posted:** Tue Jul 18, 2017 12:34 am

Thanks for keeping us posted on the outcome.

It's surprising how much that doesn't happen. :dead:

RS2001 · **Posted:** Sun Jul 30, 2017 4:11 am

Good morning at all, I have the same problem with my KJ I changed three turbines and all sensors, removed the CAT and still have the P0299 that appears after 20/30 min. The car is currently in an official BOSCH center hoping to find the problem, in addition to the sensors I also replaced the control unit and clean the aspiration duct, but nothing. If I get news I'll keep you up to date. P.S. I had written a similar post, but it has remained unresponsive. Regards R.

TKB4 · **Posted:** Sun Jul 30, 2017 10:15 am

Sorry to hear your problem persists
I believe part of the difficulty with members trying to help is understanding your translation.
I read your posts and I believe you have.
1. Had mechanic check and or change Turbo 2 or 3 times
2. had mechanic check Vacum tubes which you call low pressure tubes
3. Intercooler has been checked. It should be pressurized to test it for leaks.
4. Sensors at least the MAP MAF and Vacum Solenoid sensor and filter. I want to make sure you have checked the Turbo with direct know good vacuum by bypassing the vacuum solenoid once normal vacuum to that point is confirmed.
Have you checked or replaced any other sensors such as the IAP sensor also called the Mercedes sensor located near the MAF sensor?
5. You said the mechanic felt a hiss. If this was one of the hoses from the intercooler to the turbo or intercooler to flow control valve mounted on the intake , This a very common problem with this vehicle and if leaking would cause loss of power.

1.Has the hose that connects the lid of the air filter box to the turbo been checked? This hose often gets cracked near its connection to the turbo.
Any of the gaskets in the intake system could also be leaking such as the ones between sections of the flow control valve also sometimes described as the throttle body by some.
There is also the possibility that the turbo arm is not adjusted correctly so it isn't able to react to the sensor information fully.
2.The tube from the PVC / CVC could also be a source of leak. Has this been checked?
3.Does the jeep run normally just with low power ? Is it in what we call Limp Mode?
4. I am not sure we understand about the RPM . Will it go above 1800 RPM in park?
5. Was the intercooler pressure tested ?

Flash answered as best as he could given the translation barrier. Many others on forum are more knowledgable than I and are willing to help as we are able to.

We don't know for sure exactly what the mechanic checked or how he checked it.

If you followed the discussion with Matt, he checked most everything that could be checked.

Pictures of sensors etc. would confirm we are talking about the same component.

Data such as pressure readings from the sensors would be helpful.

Clean all connections and grounds including the one under headlight area in front of the battery tray.

I will check back on your progress.

It may be easier to confirm or explain each step so we understand what has and has not been done.

RS2001 · **Posted:** Mon Jul 31, 2017 10:13 am

Sorry for my English, the bosch official center today told me that it's all perfect (sensors, turbine, intercooler etc.) and that sure is a simple thing but it's not easy to find it .... When I run there seems to be a Electrical contact and the car for a few moments is fine then come back as before. We'll see the news in a few days.
P.S. I was thinking of checking the continuity of the cables from the control panel terminal to all the sensors even if I have no errors in the control unit, only P0299 after the usual 20/30 min. What is the part that can send the car in recovery without giving errors in the control unit?
regards Riccardo

RS2001 · **Posted:** Fri Aug 04, 2017 3:16 am

Good morning,
List all that has been done: 1, check all vacuum tubes; 2, replace the MAP-MAF and solenoid sensors (no IAP); 3, removed catalyst; 4, replaced the control unit; 5, replaced 3 turbines; 6, EGR off; 7, metal plate; 8, checked inteercoler with compressor (?); 9, checked suction manifold. The car when powered on accelerates alone up to 1800 rpm and then returns to 800 rpm, on the road by changing the "N" and accelerating beyond the 2000/2500 rpm the problem is not there, just stay over 2500 rpm, The machine does not trouble, just skidding under 2500 rpm the control unit goes into recovery.
Thanks in advance for the help
R.

TKB4 · **Posted:** Sun Aug 06, 2017 5:22 pm

Still not sure i understand totally, but things associated with the underboost code could send the jeep in to limp mode. The IAP or mercedes sensor next to the MAF sensor on the air filter lid can still be the cause, not sure how the bosch center checked it. Another thing to check for weird persistent problems like this are the electrical ground locations especially one under the driver side front headlight in front of the battery tray on the left hand drive north america model. It isn't even in our Factory Service Manual. Might be good to get a list of things they checked and what each check showed. Again it would be helpful to have pictures and OBD diagnostic data . Here is picture from the NOOB guide: The IAP sensor is barely visible below and to the right of the MAF sensor the actual lid hidden mostly by the metal refrigerant tube

http://colorado4wheel.com/images/libby/enginebay1.jpg

RS2001 · **Posted:** Thu Aug 10, 2017 10:34 am

Good morning, thank you for the answer, I will control the mass cable behind the lighthouse, but what I can not understand is because I do not have a bug at the controller but only the p0299 after 20/25 minutes that the machine is on. The machine is in recovery right away without error code.
P.S. Where can i buy IAP sensor online?
Thanks again for help R.

Ongoing P0299 underboost problems

Who is online