Transmission lost all forward gears, code P1680

1996 CHEVROLET BLAZER
123,000 MILES • 4.3L • 6 CYL • 4WD • AUTOMATIC
Avatar
BOBBLUESEA
  • MEMBER
  • 1 POST
Departed freeway. Pulled away from exit ramp and lost all forward gears in about 10-20 yards. No forward gears but strong reverse gear. Check engine light had been on since I bought it and have driven it a few thousand miles and the only code is P1680.
Sep 17, 2020 at 2:26 AM
Advertisement
Avatar
ASEMASTER6371
  • ✓ASE Certified Mechanic
  • 52,796 POSTS
  • ASE Certified Mechanic
Good morning,

The forward is controlled by the forward clutch pack inside the transmission. Chances are that these clutches have failed and will not allow forward movement.

https://www.2carpros.com/articles/automatic-transmission-problems

I would drop the pan and see if there is any metal in the pan or on the magnet.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

This sounds like either a rebuilt or used transmission will be needed.

https://www.2carpros.com/articles/transmission-replacement-removal-manual

As far as the code, can you verify the code number? 1680 does not show in my code list.

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

Roy
Image (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Sep 17, 2020 at 4:16 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.