Please help. Transmission not shifting

[EgyptianAviator]

Hey guys,
I own a Chevy Tahoe LT 2007 model automatic transmission fully stock nothing custom.

Yesterday my family and I were travelling to a place 400 km away from home. As we were heading into a rest stop which is half way through the journey (about 190 kilometres through the journey) we had to go through a small strip of unpaved road that was a bit bumpy.
However, we found out that the rest was closed. So, we reversed back and got back on the highway. However, directly upon accelerating to cruise speed the car had quickly jumped to high revs (about 3700-4000 max)without accelerating past 120 Kmh. Ofcourse i couldn't keep it this way so i had to take my feet off the pedals and maintained 3500 revs and that kept me at 110 Kmh which I think is about 70 Mph. I had to complete the journey and back again which is about 630 kilometres at this speed.
I can't feel the transmission shifting past second or third gear and I think that might be the problem. However, I don't quite know what is its's cause or how to repair it.
Ive searched alot through the forums but got no where near a conclusive answer, but I think it might be something called "Limp Mode".
Please I would like a conclusive answer about this matter as I really use the car alot on long routes.
Thank you for your time,
Mohammed El-Dakamawy

 

[Modded]

You lost a gear somehow in your transmission. If your Tahoe was in limp mode you would see a "Reduced Engine Power" or similar message somewhere on your DIC in the dash. The DIC is the little LCD that shows the vehicle mileage and other info.
Unfortunately, there is no way to diagnose that over the internet with certainty because one of many problem could have caused your issue depending on the exact gears that are out.
Best thing to do is to take it to a good transmission shop and have it looked at.

 

[EgyptianAviator]

You lost a gear somehow in your transmission. If your Tahoe was in limp mode you would see a "Reduced Engine Power" or similar message somewhere on your DIC in the dash. The DIC is the little LCD that shows the vehicle mileage and other info.
Unfortunately, there is no way to diagnose that over the internet with certainty because one of many problem could have caused your issue depending on the exact gears that are out.
Best thing to do is to take it to a good transmission shop and have it looked at.

Thank you very much sir. And it's true nothing different has been displayed on the DIC. As a matter of fact the DIC at an instant in the trip after that fault shutdown completely, even the radio screen and the AC screen that deal with the rear climate zone. But then is got back all by itself after about 20-30 minutes.
I will have it checked out by a tranny mechanic.
Once again my most sincere thank you for your quick reply.

 

[Modded]

No problem Mohammed!

 

[EgyptianAviator]

Any body else gentlemen?