2020 3500 AT4, second limp mode event in 8 months - could use some advice

[blamkin86]

Hi all, I have a 2020 Sierra HD AT4 that I really like. It has a fourwheel camper on it; we drive all over utah back country camping and having a great time offroading as much as this thing can do.

 

Unfortunately, for the second time in about 8 months, I've gotten the dreaded limp mode warning for "emissions repair."

 

First time, long story short; turned out to be the def tank. Had to leave the truck in Grand Junction at the GMC dealer - they were really good to us, but it did take 3+ weeks to get the truck back, plus a rental car, plus a return trip, etc etc.

 

GMC paid for the rental car, and even gave us the "CBGC" plan which pays for 10 future oil changes and a couple other minor things.

 

This time, same deal as before. I was on a long weekend trip. Stopped in Leadville CO for a burger. Got back in, and got the "170 miles to limp mode" message.

 

I dropped the truck at the local dealer this time (O'Meara) and they are way backed up and may not get to me for a week or two. They did scan the codes, the MAF and intake air temp sensors are either bad, or the wiring to them is. The parts, to me any way, appear to be under warranty.

 

So,

 

My issue is, we go offroad a lot. I can't guarantee I'll be within 170 miles of a dealer all the time.

 

I really want to keep this truck - not only do I love how it tows and goes offroad (for a 3500), but I'm within a month or two of having it paid off.

 

I am wondering if any of the programmers out there would let me repair my truck and reset these non-trivial codes so I can keep going and fix stuff like this on my own time? I certainly have the skills to fix either a wiring harness or plunk in a couple sensors under the hood.

 

I read the Banks iDash can reset some codes, even do a forced regen. But if the iDash can't reset this type of code for me, it's not really worth it.

 

I could trade this thing in on a newer one, but, I don't really want to pass this problem onto someone else. I am frustrated of course; only 49k miles on this one. I've also added a bunch of offroad lights and would probably have to replace both bumpers before trade in if I want to keep the lights for the next truck.

 

Love to hear any advice. Calling GMC, again. Wish me luck.

[blamkin86]

Oh yeah, no mods. Just some lights wired to the upfitter switches, and a dual ViAir compressor on the snowplow fusible link. Fox shocks if that matters -but no other mods, even replaced the stock tires with the same goodyears.

Edited August 2, 2023 by blamkin86