I have an '02 Supercrew with AOD. When I slow down, either by braking or coasting, the truck goes down to about 400rpm's before downshifting. This happens with each gear change. 4th to 3rd, 3rd to 2nd, etc. If I push the button to turn the overdrive off, this doesn't happen, it shifts at 700rpm's. This problem is not intermittent, it happens every time I slow down while in overdrive. Does anyone have any ideas? I'm a little above moderately handy and can perform most maintenance tasks with some guidance. For this issue, I need some help. Thank You in advance.

 

The AOD hasn't been used since the early/mid 90's - do you have a 4R70W or 4R100? Check the TRANS code on the door jamb sticker.

 

The TR code on the sticker is the letter "U". I'm not sure what that tells me.

 

"U" means 4R70W.

To diagnose this you need a scan tool that can look at live data so that you can see what the computer is seeing, and what it is sending.

 

Thanks Guys, I'll get this checked at a dealer tomorrow.