Engine reduced power light after idiling

[Jd908B]

Does anyone else have this problem if I sit in Park with the engine running as soon as I put the truck back in drive it goes into reduced power mode and I have to shut the truck off and restart it twice to clear it but the check engine light stays on for awhile 4 trips to the dealer and they can’t explain it any thoughts? 

2016 Silverado ltz 5.3 

[newdude]

What codes is it setting? 

[Dnt]

Tell us about your trucks mods......Example: If you have added driving lights behind the grill and possibly damaged the grill shutters? You have added an oiled CAI? You have added a procharger? Is there a accident in this vehicles past (maybe a salvage title?) ? You see where I am going, just let us know if this is a stock unit as those symptoms would be very unusual for a stock truck. Maybe your dealer service department is incompetent too? That is very possible as I have had the unpleasant experience of finding an incompetent dealership service department here locally myself. 

[Jd908B]

Completely stock I bought it bran new in 16 it’s been doing this off and on since it was a month old the dealer says it’s a transmission shift parameters code they clear it but it doesn’t fix it 

[Jd908B]

1 hour ago, newdude said:

What codes is it setting? 

Transmission shift parameters need reset 

at least that’s what the dealer says they have done it a few times but it doesn’t fix anything 

[Dnt]

Yes that information is helpful. Take your truck to a dealer that has a better service department, you can use any GM dealer that you want to, you are NOT locked in at the sorry arse dealership service department where you bought your truck.     

[Epsilon Plus]

This is an unacceptable condition. A different dealer and trying to get the GM brass involved is warranted.

 

When you get to the new dealer, have them pull the GMVIS history (they probably will anyway) and get that history since new noticed by a GM someone who will fix it, buy it back, or offer a deal you can't refuse on a trade.

 

This issue is a potential safety concern given the right circumstances.

[Jd908B]

27 minutes ago, Epsilon Plus said:

This is an unacceptable condition. A different dealer and trying to get the GM brass involved is warranted.

 

When you get to the new dealer, have them pull the GMVIS history (they probably will anyway) and get that history since new noticed by a GM someone who will fix it, buy it back, or offer a deal you can't refuse on a trade.

 

This issue is a potential safety concern given the right circumstances.

I have already made an appointment at another dealer we will find out on Tuesday what they have to say 

[Jd908B]

Ok so after two more trips to a different dealer they were able to finally figure out the problem and fix it it was the in and out speed sensor on the transfer case 

they also replaced the vacuum pump for the brakes because I noticed the brake pedal getting extremely hard when tapping the brakes more than twice 

[US Dashworks]

10 hours ago, Jd908B said:

Ok so after two more trips to a different dealer they were able to finally figure out the problem and fix it it was the in and out speed sensor on the transfer case 

they also replaced the vacuum pump for the brakes because I noticed the brake pedal getting extremely hard when tapping the brakes more than twice 

my 2014 had this brake issue too, did they say anything about power steering fluid mixed in with brake fluid?

[Jd908B]

No they didn’t say anything about fluid just that they see it often