let off the gas going between say 17-19 MPH the transmission will slam hard into third gear?

2011 CHEVROLET EQUINOX
154,000 MILES • 2.4L • 4 CYL • 2WD • AUTOMATIC
Avatar
CCALE04
  • MEMBER
  • 21 POSTS
i bought the vehicle listed above in December 2022 and the car for the most part runs just fine outside of the transmission will shift completely fine through all 6 gears as long as i stay on the gas. Ff for some reason while going through a parking lot or turning a corner i happen to let off the gas going between say 17-19 MPH it will slam!!! hard into third gear. like i said before if i doesn't happen to let off the gas as it shifts its fine and only does it in 3rd, is common for the 6T45 transmission?
Feb 27, 2023 at 11:20 PM
Advertisement
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,256 POSTS
This sounds like you have an input shaft sensor that is going out, but we should run the codes to see what comes up. This guide can help you and I have included the location of the sensor as well. Also, we should check the level of the transmission fluid.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

This generic guide can help but please check the instructions for your car below:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

Check out the images (below). Let us know what happens and please upload pictures or videos of the problem.
Images (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Feb 28, 2023 at 3:19 AM
Avatar
CCALE04
  • MEMBER
  • 21 POSTS
The only code that came up is P0420 which the mechanic i purchased it from told me about in advance. the odd knocking and rattling i figured would throw some kind of code but nothing.
Feb 28, 2023 at 4:35 AM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,256 POSTS
Can you upload a short video of the noise so I can hear it? That way I can tell for sure what's going on. Also, when the input shaft sensor goes bad it doesn't always leave a code, FYI.
Mar 1, 2023 at 10:27 AM
Avatar
CCALE04
  • MEMBER
  • 21 POSTS
The sound is completely unrelated to the transmission shifting issue when I responded I didn’t realize my 2-part original question got split into separate questions on here and is unrelated. Sorry about that.
Mar 1, 2023 at 10:36 AM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,256 POSTS
No worries, we only handle one problem per thread.
Mar 1, 2023 at 11:01 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.