Automatic quick downshift at 44 mph

Post by **FireFox31** » 15 Dec 2021, 22:57

My 2000 V70 NA automatic is indecisive about which gear to use at 44 mph. When driving 44 mph at 1900 rpm in 4th gear on fairly level ground, the drive train power will seem to cut out for a split second. I think the car is shifting to 5th then immediately back to 4th.

For the past month, this has happened predictably, such that I know which stretches of road cause it. I bet the cooler New England temperatures affect it because I think it happened last winter (when I first got the car and was learning its problems). Two months ago, I did my first transmission fluid drain/fill but haven't yet done the other two.

What could this be? Is there a way to diagnose it, perhaps with monitoring software on the part of road where I know it will happen? Maybe I should get the VIDA laptop.

Post by **abscate** » 15 Dec 2021, 23:16

I’ve almost written this up, but never got to it. It’s a peculiarity of ME7 and DENSO cars with AT that when you lift, then up come back on the gas lightly, the torque converter unlocks for a brief second. You get a 1/2 second blip in rpm then it settles back to light cruise. This is most noticeable in the 40-50 mph regime

Maybe limited to the 1999-2000 models