Random shut off on the 2020 6.2

MeatMonsterAT4 · Jul 15, 2025

Hi Guys, I was minding my own business today when I backed out of the garage and the truck completely shut off. No lights or nothing. Struggled to get fuel like it was choking. Finally got it to get some fuel and drove a few miles and the tach needle struggled and then finally the Check Engine light came on. Pulled over and called the wrecker to haul me to the dealership. Not gonna take any chances today, so they're gonna load it up and haul it. Any feedback whatsoever is welcome. 90,000 miles and mostly bone stock except for the K&N air filter and a leveling kit. I'm the 2nd owner. Thanks in advance.

***Update with context***
I got the truck hauled to GMC and the check engine light came on so the dealer read the code as "Mass Air Flow Sensor" issues. So I did remove the K&N Synthetic air filter and clean it yesterday morning and reinstalled without oil (because it said No Oil) and I guess somehow that triggered these issues? I guess I should have put that in my original post but I've been cleaning my air filter on all my past vehicles with no issue. So the service manager said he will clear the code and take the air intake kit apart and see if something is trapped in there or something and then drive it again. My question is does something have to be reset once I clean the filter and reinstall it?

R467X · Jul 15, 2025

MeatMonsterAT4 said:
Hi Guys, I was minding my own business today when I backed out of the garage and the truck completely shut off. No lights or nothing. Struggled to get fuel like it was choking. Finally got it to get some fuel and drove a few miles and the tach needle struggled and then finally the Check Engine light came on. Pulled over and called the wrecker to haul me to the dealership. Not gonna take any chances today, so they're gonna load it up and haul it. Any feedback whatsoever is welcome. 90,000 miles and mostly bone stock except for the K&N air filter and a leveling kit. I'm the 2nd owner. Thanks in advance.

Lots of topics on this. You might need a new engine. Could be fuel pump or something with the fuel system too ( best case scenario).

Johnv76 · Jul 15, 2025

My bet is the fuel pump, and or clogged fuel filter.

MeatMonsterAT4 · Jul 16, 2025

Ive put in a support call to K&N to ask them what I did wrong cleaning the filter and waiting to hear back from them. The dealer still has the truck and says it's flashing a code of mass air sensor issues. So I guess we wait.

roy826ex · Jul 16, 2025

Fuel pump control module my 2023 6.2 just left me on side of the road with 16k miles on it. Code was P129F which was the fuel pump control module. Fixed under warranty but left me stranded then limped to nearest dealer about 17 miles away cause I was 400 miles from home. Quick fix if the part is In stock which mine was. Onstar gave me the diagnostics code which dealer saw same thing once I got it there.

MeatMonsterAT4 · Jul 16, 2025

Ok update. Good news. I spoke with K&N and they said when that happens its because I didn't let the air filter thoroughly dry out before I reinstalled and the truck inhaled damp wet air and tripped the sensor/code. So the dealer inspected everything and couldn't find anything out of the ordinary. They reset the code and it stayed gone. Picked up the truck and it's running smooth again like nothing ever happened.