My 07 5.9 is not downshifting past third when I roll up to a stop. It won’t even go into third if I manually try to make it. Because of that, when I go to accelerate off a stop it hesitates until it drops down into first and then it takes off fine. I can also force it into first by “goosing” the gas pedal while holding the break, and then it takes off fine. It will also act normal if I’m rolling 25 mph through town and keeping it in second, then it’s fine. Only when I get to third it won’t downshift without help.

I’ve researched here and in other forums but can’t find the exact issue I’m having. I’m leaning towards replacing the transmission gov/solenoid with the GM one that I see other posts about in hopes that will fix it but I hate to go through the time and money if someone on here has had the issue and knows what is wrong.

 

Put a line pressure gauge on the gov test port. I believe it’s the rear most pipe plug on the passenger side. It should read about 1psi for each mph up to I think 30ish, then it reads I think 2 psi for each mph. I don’t have the book handy, but I recall reading that the pressure scale changes after a certain vehicle speed to prevent excessive upshiifts/downshifts under load at higher speeds

whatever the calibration, if you have more than a couple psi of gov pressure at a stop, then most likely the solenoid/transducer is defective.