P0402 CEL

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May 6, 2019 | 04:09 PM

6.7Scorpion

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P0402 CEL

Not much on here when I search this section so just curious what you guys know about this code. I see its for the EGR system but not sure what is the event really that causes this, valve not functioning, too much/too little flow or something else. I have ez lynk but still haven't deleted my truck as I was just waiting till around the 15,000km mark just in case I noticed something not right with a new truck. I did put an emissions intact tune in last summer for a couple weeks just to see but reverted back to stock as shifting felt off. That was in august of 18. I just dropped an AFE dry flow filter in my truck before taking off on a 1500km round trip (4 mountain passes ) and about 200km into the trip the truck felt a little under powered going up the first pass. Well I went to pass a person and really had to put my foot into it as it wasn't going and then the truck hiccuped and CEL came on. I had the ezlynk so I read the code and cleared it but truck still ran funny. boost would only hit about 14psi and ran at that all the time and needed 3rd gear to maintain speed up the mountain. 20 mins prior to this starting to happen I had the DEF fluid 800km to empty pop up. I don't know if its is any relation but it was a detail that happened around the time of the CEL. I was worried to turn the truck off and maybe not starting so I ran it over the pass and the next one till I got to a town and had cell service once again. looked at the air filter since I just put it in and tugged on some of the hoses wondering if there was a boost leak or something. checked the wires on the MAF sensor and made sure something didn't happen to that when I had the air box open. Well we grabbed a bite to eat and went back out to try luck and the truck seemed to run fine and was seeing the turbo vanes cycling and boost hitting 25psi. (I forgot to check if vanes were changing before and the wife ran the phone while I was driving and mechanical isn't her thing). Im home now and truck has run good for last 1000kms. I will take the truck in in next few weeks and they might have to clear the code in the background still ? not sure if ezlynk really fully clears or not. Anyways, just wanted to hear some input from people I might trust a little more then I do the dealership. Thanks

May 7, 2019 | 07:31 PM

THOM/CJ KR 350

Cross-Country

Joined: Feb 2017

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From: Peyton, Colorado

I have the same issue from time to time. I just clear it and keep going. Your intake system is flowing too much air. I have an S and B cold air intake and get the CEL happens when I carry my camper and get on it. So much for "won't set CEL"!

May 7, 2019 | 08:47 PM

6.7Scorpion

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Quote:

Originally Posted by THOM/CJ KR 350

I feel this probably gets in to the programming but shouldn't it only pull enough air that its calling for by adjusting vane position? is the injection rates just not keeping up or not enough fuel for the mix ?

Jun 6, 2019 | 10:41 PM

Shady Camper

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Joined: Jul 2017

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From: Turlock, CA

I'm currently camping at 7500 ft in the Sierra Nevadas. Tried to drive out a Regen and it was acting wierd, soot dropped but it still shows DPF 70%. This morning upon start up, got a cel. Checked and found it to be P0402. Truck runs fine and I'll be pulling my bumper pull trailer home tomorrow. Upon researching, I found a TSB I'm sure I'll hit another Regen and everything will be ok back on flat land. If not, it'll go to the shop. I'm glad most of my travels tomorrow will be headed down hill.

Jun 7, 2019 | 10:11 PM

Shady Camper

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Joined: Jul 2017

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From: Turlock, CA

So, I made it home, no problem. Regens happened at 125 mile intervals, which sucks, since it was 400-430 miles between events. Had two happen, one coming down the hill and the second as I was taking the trailer back to storage. Seems the second one cleared the CEL. The whole trip home it ran fine, but did seem to be short on power on some of the steeper hills. I have an appointment Monday to have it checked, I'll report back when get it back. My truck was built in early October 2016 and my travel trailer comes in at 10,500 lbs or so loaded (last time I weighed it).

Jun 12, 2019 | 01:00 PM

Shady Camper

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Joined: Jul 2017

Posts: 71

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From: Turlock, CA

So I got it back from the dealer after two days. They initially didn't want to do anything since the CEL clear itself. I gave them the TSB number and told them to read it. Got a call back at the end of day one saying they were going to re-flash/updated everything per the TSB. The tech also told me he found my driver's side battery leaking and replaced both batteries, since each had a bad cell. At the end of day two, I got a call it was ready. When I spoke with the tech, he was pretty frustrated since the dealership network was experiencing issues with the internet for most of the day, he couldn't get into my as built files and the update. He told me once the internet was stable enough to attempt the re-flash, it was done in a matter of minutes. He said it should be able to adjust to altitude a lot better now and my regens should return to normal. I'll see what happens next week as I'm towing an 8k utility trailer up to about 6k ft.

For now I'm happy, new batteries are never a bad thing!

Jun 12, 2019 | 01:18 PM

Sarge261

Logistics Pro

Joined: Feb 2004

Posts: 4,460

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From: The Land Of Time

Nice to hear they took care of you Shady...I have a stack of recalls on my truck but I don't have a great dealer around here, I also have leaking batteries but I was just going to replace them myself and save some aggravation's. Report back after you tow and see if that fixed your regen issues.

Sarge