2005 Silverado stuck in 3rd gear

[Tdallas]

I have a 05 Silverado Z71 5.3l with 4L60E transmission. Transmission starts out in 3rd gear and won't shift automatically but can manually shift up and down. Replaced fluid /filter/TCC solenoid/A&B solenoids but still having the problem and getting codes P0740,P0758,P085,P2761. Any help?

Edited April 27, 2025 by Tdallas

[richard wysong]

Welcome to the Forum! ALWAYS post the code definitions along with the codes, there are over 18000 possible codes and no one remembers them all. Most folks will skip over this post rather than take the time to look them up, myself included

[davester]

charm.li will have diagnostic produres for those codes.  gm recommends working the codes from lowest to highest, one at a time.

 

did you do any work to the truck recently, or did this all just suddenly happen?

[Tdallas]

No I didn't perform work prior to it starting this issue. It started doing it intermittently last few days to about a week so I changed out the sensors the codes showed and did a fluid/filter change hoping it would solve it. More research shows apparently its popular to have a ground issue to cause this but have not investigated that yet. I'm military and on a trip for next few weeks so can't do anything until I'm home but please send any tips 

[Tdallas]

On 4/27/2025 at 5:29 PM, davester said:

charm.li will have diagnostic produres for those codes.  gm recommends working the codes from lowest to highest, one at a time.

 

did you do any work to the truck recently, or did this all just suddenly happen?

No I didn't perform work prior to it starting this issue. It started doing it intermittently last few days to about a week so I changed out the sensors the codes showed and did a fluid/filter change hoping it would solve it. More research shows apparently its popular to have a ground issue to cause this but have not investigated that yet. I'm military and on a trip for next few weeks so can't do anything until I'm home but please send any tips