Transmission code P0733?

2021 RAM 1500

57,000 MILES • 5.7L • 4WD • MANUAL

MGOBLUE78

MEMBER
20 POSTS
FOLLOW

Hi, this may be a long shot but I’m wondering if there is anything I can do or check to help figure out my trans code P0733. I have a 2021 Ram 1500 4x4 with 5.7 and 8 speed transmission. Shortly after I purchased my truck from a local Dodge dealer I was having issues with it shifting into 4 gear. It finally got so bad engine light would come on and put the truck into limp mode. The only way to drive it was to clear the code. The dealer couldn’t get it to act up and obviously couldn’t see anything diagnostic/computer wise because I had to clear codes to drive it. They did check trans fluid level and said it was clean and full. After trial and error, it will definitely through the code when truck is cold and I go straight to drive. Ambient temp doesn’t seem to matter. If I have to reverse(back out of my driveway) on a cold start then to go drive it seems fine. Is there anything external on these transmission to check? I had a ‘05 Dodge Grand caravan with very similar problems that ended up being a bad trans control solenoid and a broken speed sensors. I’m praying it’s something simple like this, lol. Any help you could give would be greatly appreciated!

Apr 30, 2026 at 2:31 PM

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.

STRAILER

AUTOMOTIVE REPAIR CONTRIBUTOR
54,178 POSTS

Hello,

A P0733 means Gear 3 Incorrect Ratio. In simple terms, the transmission control system commanded a certain gear ratio, but the input/output speed readings did not match what the computer expected. Even though you mentioned a problem “shifting into 4th,” the code itself points to an incorrect ratio event involving 3rd gear or the transition around that shift. So I would try replacing the input shaft sensor sensor and if that does not work there might be something wrong internally with the transmission. Here is the location of the sensor. You might want to try servicing the transmission as well, Make sure the correct ZF/Lifeguard-style 8-speed fluid or Chrysler-approved equivalent was used. Wrong fluid can cause ratio and clutch apply issues. IF the code comes up again do not clear it before taking it to the dealer. I have also seen the valve body pack go out and cause this issue as well FYI. Check out the images (below). Please let us know what happens.

Image (Click to enlarge)

May 1, 2026 at 3:56 PM