2017 GMC Sierra 6.2 8 Speed Limiter at 84MPH?????

Tanner Smith · October 15, 2020

Hey guys, I have a 2017 GMC Sierra with the 6.2L and the 8 speed .My top speed is only 84 mph. has anyone else seen this on theirs? it used to be 98 but for some reason it stops at 84. May it be transmission electronics messing up? It still has the factory warranty and is getting taken in on the 28th of October, but just curious to see what and why it has happened. It has 47,000 miles on it. Thanks

GrumpyAeroGuy · October 15, 2020

I can't answer your question specifically, but I can offer this up.

I have a 2016 5.3l 8sp.

Not sure where it tops out, but I know I had it past 85 mph briefly more than a few times. 84 seems odd to me, as certain areas of the country have 75mph speed limits on interstates I seem to recall....

Have it checked out.

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sldhead700 · October 15, 2020

I'm sure mine is still close to that hundred mark.... ( I don't remember exactly where it kicks out at)
I was over 90mph last week with no problems.
2017 6.2 8 speed max tow with 44,000 miles.
Not sure why yours has suddenly changed.....

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sldhead700 · October 15, 2020

I can't answer your question specifically, but I can offer this up.

I have a 2016 5.3l 8sp.

Not sure where it tops out, but I know I had it past 85 mph briefly more than a few times. 84 seems odd to me, as certain areas of the country have 75mph speed limits on interstates I seem to recall....

Have it checked out.

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Yes, there are several that are 75mph west of the Mississippi.
Some are even 80mph....[emoji106]

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GrumpyAeroGuy · October 15, 2020

Yes, there are several that are 75mph west of the Mississippi.
Some are even 80mph....[emoji106]

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Love it

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Horacio · October 15, 2020

2015 Sierra Denali here with the 8 speed. Mine hits 92, but I once saw pics on here of a driveline that wrapped around itself after hitting 92 mph, so I’m happy to come off the gas pedal once I get the passing out of the way.

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Artelt · October 15, 2020

I’ve hit 98 on the speedo, but running 35s my speedo isn’t corrected. GPS said 103mph so [emoji2369] 2017 5.3 8 speed

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M1ck3y · October 15, 2020

Isn't there a teen driver mode on these trucks? Maybe its in that mode?

Yeah my truck has this feature, I should almost set it up for myself. lol

Edited October 15, 2020 by M1ck3y

rav3 · October 15, 2020

8 hours ago, M1ck3y said:

Isn't there a teen driver mode on these trucks? Maybe its in that mode?

Yeah my truck has this feature, I should almost set it up for myself. lol

Good point M1ck3y.....If teen driver mode is "checked" the truck/car wont go over 85 MPH. I bet that's the issue. Now you'll need to remember your code to UNCHECK it, I think.

Here's a video on setting up Teen driver https://youtu.be/Q4vFEblzklk

Edited October 16, 2020 by rav3

sldhead700 · October 15, 2020

Good point M1ck3y.....If teen driver mode is "checked" the truck/car wont go over 85 MPH. I bet that's the issue. Now you'll need to remember your code to UNCHECK it, I think.

That would totally make sense, I would check into that being your problem too!

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