2020 Jeep Wrangler Diesel P0299 and P049B codes

[wildtaco]

Great information, Thanks.
Question, why is it that after resetting the codes it runs normally for a short time? Is it taking that time to see the faults? Thanks in advance for the answers.

I'll have to check the LP EGR Differential pressure sensor, Not sure how to check the cooler. I have checked the turbocharger inlet and outlets for leaks. Will check the MAF sensor. The EGR valve checked via the Diagnostic tool, it operated as commanded without fault.

Thanks again for the info and advice.

I drove across the entire US like this lol. Clear codes, drive for 1-6 hours, limp mode, repeat. It takes a while for the system to catch the fault again.

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[DylanM]

Great information, Thanks.
Question, why is it that after resetting the codes it runs normally for a short time? Is it taking that time to see the faults? Thanks in advance for the answers.

I'll have to check the LP EGR Differential pressure sensor, Not sure how to check the cooler. I have checked the turbocharger inlet and outlets for leaks. Will check the MAF sensor. The EGR valve checked via the Diagnostic tool, it operated as commanded without fault.

Thanks again for the info and advice.

As wildtaco mentioned, it often takes several minutes of operation before the codes will set again after they're cleared. In the case of P049B, the monitor for the conditions to set the code doesn't start running until the engine coolant temp is above 131°F and charge air cooler temp above 43°F, along with the LP EGR in a flow condition.

In your checks of the EGR valve with your scanner, were you testing the high pressure EGR valve or the low pressure? Your fault is for the low pressure EGR. Of added note, there isn't an abilityfor the PCM to see the specific variable position of either EGR valve, the PCM calculates the position of each based on the signals from each respective EGR temperature sensor.

If you don't already have access to one, you can find a service/workshop manual here: https://www.jeepgladiatorforum.com/...-service-and-repair-manual-free-online.78333/
Troubleshooting information for your powertrain fault codes is found in the "DTC 3.0L Diesel - Diagnostic Code Index" section, while theory of operation and service information for the EGR system is found in the "ENGINE PERFORMANCE 3.0L Emissions Control" section.

 

[crimsontidewins]

As wildtaco mentioned, it often takes several minutes of operation before the codes will set again after they're cleared. In the case of P049B, the monitor for the conditions to set the code doesn't start running until the engine coolant temp is above 131°F and charge air cooler temp above 43°F, along with the LP EGR in a flow condition.

In your checks of the EGR valve with your scanner, were you testing the high pressure EGR valve or the low pressure? Your fault is for the low pressure EGR. Of added note, there isn't an abilityfor the PCM to see the specific variable position of either EGR valve, the PCM calculates the position of each based on the signals from each respective EGR temperature sensor.

If you don't already have access to one, you can find a service/workshop manual here: https://www.jeepgladiatorforum.com/...-service-and-repair-manual-free-online.78333/
Troubleshooting information for your powertrain fault codes is found in the "DTC 3.0L Diesel - Diagnostic Code Index" section, while theory of operation and service information for the EGR system is found in the "ENGINE PERFORMANCE 3.0L Emissions Control" section.

Downloaded it, Thanks!

 

[Downtrail]

Have you made any more progress on this one? I have a similar set of codes (P049B and P0299) with the Jeep going into limp mode. I have it at a dealer to diagnose, and they think it's the low pressure EGR cooler, and they may be right, but their procedure is to remove the body to get access to the back of the engine to replace it. I may bring it back home to do some checks myself before I decide how to move forward.

I'll let you know if I learn anything new.

 

[Downtrail]

I also meant to mention that when it went into limp mode the first time while on a road trip last month, I took it by a dealer that diagnosed both the turbo and low pressure EGR cooler had failed and needed to be replaced. Turbo replacement would be covered by the 100k/5 yr powertrain warranty, but EGR system is not powertrain according to Jeep.

 

[crimsontidewins]

I also meant to mention that when it went into limp mode the first time while on a road trip last month, I took it by a dealer that diagnosed both the turbo and low pressure EGR cooler had failed and needed to be replaced. Turbo replacement would be covered by the 100k/5 yr powertrain warranty, but EGR system is not powertrain according to Jeep.

What do they mean by failure, as far as the low pressure EGR cooler failing? I would think that would mean it is leaking. I have no indication that mine is leaking. Also, have you reset everything, i.e. clearing the codes. I have done this multiple times searching for an indication of the real issue. The Jeep performs as it should until the codes are thrown again, 5 mins to 15 mins. I have also recorded the turbo boost during these resets and the turbo is boosting up to 28 psi, if my memory serves. Which, to me, would be an indication that the turbo is working, until it goes to limp mode, i.e. no boost and both EGR valves to 50%.

I really dislike Dealer Service depts because I don't think that many really good mechanics works for dealers very long. That isn't to say there aren't some very good mechanics that work for dealers, there are, but I think they are far and few between.

I am meeting with a Diesel mechanic Thursday, one that was recommended to me by a relative who is a retired mechanic who didn't deal with Diesels, so I'll see what he has to say.

I will update when I know something new

 

[crimsontidewins]

Ok, I am updating with a red face and embarrassed but happy that I believe my problem is solved. I went to the diesel mechanic mentioned above and he found the issue in 30 seconds. I have been crawling all over this engine for weeks but missed it! A friend who works on cars looked and he missed it too. The diesel mechanic, with his years of experience saw it almost immediately.

Even though I have an F-250 Diesel that I've had for 19 years and have done a lot of the work on it, I still missed it.

I had a leak on the Charge Air Cooler Hose, even though I felt like I looked it over thoroughly. Again Red faced!
The reason it's been so long on the update is that a OEM Charge Air Cooler Hose was at least 2 weeks out, one of the problems owning these EcoDiesel engines is that no one, and I mean no one has the parts, even simple ones. So instead of waiting 2 weeks to get a OEM Hose I ordered an upgraded way more expensive Hose and installed it this morning.

I then went on a 30 miles plus drive without the Jeep throwing codes, so I think the problemed solved.

I really appreciate everyone who put in their 2 cents, it really helps, so thank you.
Have a Great Year and Blessings to you and your family.

 

[Vtur]

Glad you found the issue. Thanks for updating the thread as this will greatly appreciated for future members with leaking charge pipe.

 

[rharr]

I recall reading a post here where someone else had the same issue and also had a hole in the tube.

Any idea what made the hole?

 

[Vtur]

I recall reading a post here where someone else had the same issue and also had a hole in the tube.

Any idea what made the hole?

One member had a puncture from the hpfp replacement by the dealer. The cold side hose appear thin and softer than standard radiator hoses.

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