18 Denali won’t go past 85 mph

[18siknali6.2]

Hello guys I’m new to the forum I drive a 18 Sierra Denali . I’ve been having trouble with . Like a couple weeks ago , Was driving to work and truck wouldn’t go past 85 mph . I really don’t know what could be the problem . Anyone knows or has it happen to somebody else in here . Thanks ! No lights or anything came up in the dash ! 

[CamGTP]

Is the profile picture of your truck with the aftermarket rims/tires?

 

Was the computer re-calibrated for the change in tire diameter?

 

85mph is above the speed limit anyway so I'm sure some will have no sympathy for you lol.

[fishnfly20]

29 minutes ago, 18siknali6.2 said:

Hello guys I’m new to the forum I drive a 18 Sierra Denali . I’ve been having trouble with . Like a couple weeks ago , Was driving to work and truck wouldn’t go past 85 mph . I really don’t know what could be the problem . Anyone knows or has it happen to somebody else in here . Thanks ! No lights or anything came up in the dash ! 

Is your truck in valet mode? 

[18siknali6.2]

46 minutes ago, fishnfly20 said:

Is your truck in valet mode? 

No, I checked and everything is right !

[18siknali6.2]

1 hour ago, CamGTP said:

Is the profile picture of your truck with the aftermarket rims/tires?

 

Was the computer re-calibrated for the change in tire diameter?

 

85mph is above the speed limit anyway so I'm sure some will have no sympathy for you lol.

Yes it is , and I had the lift and wheels for a year now and nothing had happen, this just happen like 2 weeks ago . 

[JimCost2014]

How did the truck act when it hit 85?

 

Did it feel like the fuel had been cut off, or just would not go any faster?

[18siknali6.2]

19 hours ago, JimCost2014 said:

How did the truck act when it hit 85?

 

Did it feel like the fuel had been cut off, or just would not go any faster?

It just doesn’t go any faster ! 

[JimCost2014]

43 minutes ago, 18siknali6.2 said:

It just doesn’t go any faster ! 

Maybe it is afraid, I would be in a lifted truck traveling at that speed.

[Rockhoyle]

Did you ever find out what the problem was ? My 15 Denali 6.2 doing the same. Actually happened a couple months ago and then went away. 

[truckguy82]

You guys have to be more specific

 

does simply nothing happen when your foot goes to the floor?

 

you made it sound like you just ran out of hp

[Chris Brazas]

On 1/12/2020 at 12:00 PM, JimCost2014 said:

Mine just started doing that out of the blue yesterday.  What does this mean?

[JimCost2014]

18 hours ago, Chris Brazas said:

Mine just started doing that out of the blue yesterday.  What does this mean?

Welcome to the site.

 

I guess we established the other members truck was afraid to travel over 85 MPH because of the lift and tires

[pokismoki]

On 1/11/2020 at 3:15 PM, 18siknali6.2 said:

Yes it is , and I had the lift and wheels for a year now and nothing had happen, this just happen like 2 weeks ago . 

maybe you just noticed the speed limitation ...it was probably detuned by who ever installed the lift, usually when you lift a truck the Driveshaft needs lengthening because the yoke slides out of the tailhousing due to the lift (simple trig equation), installer might of felt a need to slow you down before you blow the tail-shaft drag racing ... unless GM has access to the speed gov via GPS on the roof

Edited June 9, 2021 by pokismoki

[BrezDenali6.2]

Ours had no speed limitations and we installed a mag-ride delete kit. We have a light for the suspension service on now and it started cutting the gas at 85mph too. We believe it to be a safety so you won't drive unsafe with a suspension issue. Hoping to get it fixed asap, you may want to check yours as well.  I hope this helps.

[Smiley78]

I have the same issue with my 2017 suburban. Before I could get up past 85 mpg . Now it shuts down at 85mph like there is a speed limiter on it. I have had the tires calibrated. I also have the suspension light come on from the factory air suspension being disconnected. Have had the 6” lift for years now and 35” tires on it, it just all of sudden started happening.