I've only heard it a few times but here's what happens. driving slowly around 35 and lightly accelerating, it's in 4th IIRC. trans downshifts to 3rd and it makes a loud hum/honk and does not accelerate. ease off the accelerator and it picks back up without a problem. I'm not sure if this is the same issue as covered in the 5-4 TSB or something else. Just looking for what the symptoms are before the ECM is reprogrammed.

 

just bringing this back to the top as I still experience this issue. The dealer wanted to keep the truck to troubleshoot. Im hesitant to do so seeing that i can't replicate the issue and it only happens once every few weeks.