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2020 at4 6.2 truck shutting off when in reverse

AT4Juan
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AT4Juan Enthusiast

AT4Juan

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Hi everyone, Im new to this forum, I drive a 2020 AT4 6.2, truck has 42,000 mil. Truck is runing good and strong,  but a while ago started to act weird, when I put the truck one reverse and I press the pedal (a lil bit, for the truck just to move, like when you in the mall) you can feel the engine like vibrating and when I put the truck on drive, it shut off (but not always), I put the truck back on park and it start right away and put it on drive and work just fine, when Im driving down the road the gruck works fine, is just when is idleling in reverse. I want to know if some one has this problem before or have any idea what it coul be

calgator73 Senior Enthusiast

calgator73

Posted
Posted
11 hours ago, AT4Juan said:

Hi everyone, Im new to this forum, I drive a 2020 AT4 6.2, truck has 42,000 mil. Truck is runing good and strong,  but a while ago started to act weird, when I put the truck one reverse and I press the pedal (a lil bit, for the truck just to move, like when you in the mall) you can feel the engine like vibrating and when I put the truck on drive, it shut off (but not always), I put the truck back on park and it start right away and put it on drive and work just fine, when Im driving down the road the gruck works fine, is just when is idleling in reverse. I want to know if some one has this problem before or have any idea what it coul be

That sounds weird and almost like your stop/start system is not right.  So when you idle in reverse engine turns off.  What happens when you shift to drive or park?  Does it restarts or is it a stall and you have to restart the engine manually in park?

AT4Juan Enthusiast

AT4Juan

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56 minutes ago, calgator73 said:

That sounds weird and almost like your stop/start system is not right.  So when you idle in reverse engine turns off.  What happens when you shift to drive or park?  Does it restarts or is it a stall and you have to restart the engine manually in park?

This happen even when the auto stop/start system is off. So, when is in reverse and I give it little gas just for the truck to move and then put it back to drive and press the gas pedal a lit bit, to start going, you can feel like the engine want to die(in some cases it dies) but if I let got the pedal, boom the truck dont shut off. And when it shut off on me, I just put the truck back to park and manually start it, and it work just fine. This happen mostly when you shift from reverse to drive in low speed, like when you at the store or at the mall parking lot when you going carefully. Is going to sound stupid, but is like when you have a weed eater and is running good in idle, but as soon as you want to start working you give it some gas and it dies, in my case it dont wappen all the time. 

AT4Juan Enthusiast

AT4Juan

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Posted (edited)

Another thing,  is in the mornings, when the truck is "cold" the rpm's are up and down, almost to the point that you can hear the truck is about to shut down

Edited by AT4Juan
calgator73 Senior Enthusiast

calgator73

Posted
Posted

I tend to agree with Tim with it being electrical.  Set your ebrake and have someone exercise the vehicle a little while you observe under the hood.  Could be simple chafing on a harness that moves ever so slightly when you shift into different positions.  Might also consider just letting it idle in park ebrake set and crawl under the truck moving harnesses by hand.  Any kind of harness issue could cause a communications issue that results in a stall.  Still under warranty?

AT4Juan Enthusiast

AT4Juan

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Update...

I remove my coldair intake tube to check the throttle body for any oil residuals from my intake and sure thing the walls and the flap were dirty and oily, not that bad but still dirty. I took it to the dealership to get it clean and most important re-learned, I was thinking to do it myself because its easy, but then the relearn thing, so naahh. They clean it real fast, I was in and out in less than 45 minutes and the truck its been running good for the last 5 days. 

Edited by AT4Juan
calgator73 Senior Enthusiast

calgator73

Posted
Posted
On 12/27/2022 at 8:04 PM, AT4Juan said:

Update...

I remove my coldair intake tube to check the throttle body for any oil residuals from my intake and sure thing the walls and the flap were dirty and oily, not that bad but still dirty. I took it to the dealership to get it clean and most important re-learned, I was thinking to do it myself because its easy, but then the relearn thing, so naahh. They clean it real fast, I was in and out in less than 45 minutes and the truck its been running good for the last 5 days. 

That is weird.  hard to believe a cold air intake tube...wait....relearn what?  There have been people who upgraded to the GM cold air intake and failed to get the calibration for the MAF complete and had all kinds of drivability issues.

AT4Juan Enthusiast

AT4Juan

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53 minutes ago, calgator73 said:

That is weird.  hard to believe a cold air intake tube...wait....relearn what?  There have been people who upgraded to the GM cold air intake and failed to get the calibration for the MAF complete and had all kinds of drivability issues.

I guess the throttle body got dirty because of the oil from the intake. Some times when you remove and clean the throttle body you need to "re-learned" or calibrated, so thats what they did. I guess is not the first time they had some one with that problem, because the mechanic ask me what was wrong, so I explain him and he was like ,"oh you put the cold air intake". He told me that the throttle body needs to be clean all the time.

calgator73 Senior Enthusiast

calgator73

Posted
Posted

Guess I learned something new.  Wouldn't have thought they would remove the TB to clean vs using upper intake cleaner.  I've never cleaned my TB...just use top tier fuel and the right oil.  Glad you got it sorted.

AT4Juan Enthusiast

AT4Juan

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12 minutes ago, asilverblazer said:

Oiled air filter?

Yes, the oil from the filter started to acumulate in the flap and walls of the throttle body 

asilverblazer Senior Enthusiast

asilverblazer

Posted
Posted
19 hours ago, AT4Juan said:

Yes, the oil from the filter started to acumulate in the flap and walls of the throttle body 

Did you switch to a paper or other non-oiled filter?

 

It's not getting too dirty from PVC is it?

AT4Juan Enthusiast

AT4Juan

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Posted
5 hours ago, asilverblazer said:

Did you switch to a paper or other non-oiled filter?

 

It's not getting too dirty from PVC is it?

I switch it to a non-oiled filter, a dry filter

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