2006 4.6l 2wd has 152K miles and 60K since last trans service. Fluid looks and smells good.

Driving at highway speeds if I let off the gas the transmission shifts to 3rd on its own. Doesn't matter if road is flat or going down hill. Keep the slightest amount of acceleration and it won't happen.

Also, when coming to a stop doesn't want to shift into 1st gear which causes a lurching at full stop and/or motor to spin up before it catches. Tonight I tried to manually put tranny in 1st at about 10 mph but didn't work and only goes back after a few seconds after full stop.

Until today was only happening after truck was warm. Today it was acting strange leaving for work.

I know the fluid needs changing, but would like to know if there could be another issue in play.

Thanks for any help!

 

So coming in to work this morning if I let off the gas it down shifts on its own to 3rd gear just like before. So I tried turning off OD to make it stop, but it actually seemed to put it in neutral instead! Very strange, but if I stayed on the gas the engine would spin up till I let off.

Could this be a torque converter problem???

If anyone has thoughts on this PLEASE share them. Thanks!

 

Anyone??

 

So last night it threw a p0731 code. Took it to trans shop today but their builder was off and other than getting the code I didn't get any answers.

Does anyone have any insight? Should I try changing the fluid today or is that a waste of time and money?

 

http://engine-codes.com/p0731_ford.html