1997 Pathfinder shifting problem

[97SnowPath]

My first post here. I don't know much about auto trannies but, I have one now and I've searched for days hoping to find an answer to my problem.

transmission seems to work smooth and well other than sometimes pronounced 1st to 2nd (not bad though). When driving at speeds of 40mph+, if I let off the accelerator and then repress, the transmission kicks down (3rd?), then rolls into 4th(?)(lower rpms), and then kicks back to 3rd (higher rpms). If I really romp on the accelerator I can get it to stay in 3rd and continue to accelerate but, usually it does the 3rd-4th-3rd thing (i.e. rpms kick up, then down, then back up again).

I've recently flushed the transmission fluid (home flush done by running a few gallons of fresh ATF through) and changed filter. The fluid level is correct.

I did the transmission diagnostic test as described in the FAQs and here's what I get. My diagnostic shows one long blink folowed by 10 short blips.

I'm considering changing out the solenoids but, I don't want to just start throwing money at this problem without having a good understanding that I'm throwing it in the right direction!

It has 111k miles. No issues with slipping, hunting, or anything other than this problem. I adjusted the TPS yesterday and it didn't help this issue.

Thanks

Modified by 97SnowPath at 12:28 PM 10/8/2006
Modified by 97SnowPath at 1:19 PM 10/8/2006

[NISTECH]

The Tps may have interal circuit problems. If you have a volt meter moniter the signal wire of the TPS. With it plugged in back probe the wire. With the key on and engine off you should see ~.5v . Place the meter where you can see it from the drivers seat. Depress the pedal all the way to the floor then slowly let off it till it reaches rest postion and watch you voltage reading. After 10 seconds do it again. Repeat this 4 or 5 times. If at any time when it is sitting at rest position the voltage starts to gradually climb up by it self you have a bad TPS. Replace it.

[97SnowPath]

I checked and it seemed to pass this test. There was a smooth curve of volt increase/decrease and a static reading when the pedal disengaged. Any other ideas?

Thanks.

[97SnowPath]

Does it mean anything that it doesn't do this when the engine is cold? Probably not since it doesn't shift into overdrive until the transmission is warmed up. Right?

It is worst when the transmission is warm. At highway speeds, if I release the gas pedal, and then repress, it winds up / thwump down to OD / then shifts back to 3rd.

3rd holds fine without OD (either locked or cold).

Am I going to need a rebuild, solenoids, or....?

Any ideas?

Thanks

[NISTECH]

It seams more its a control issue then a mechanical issue. As you said it does not use OD when cold so you wouldnt experiance it cold. This could simply be an input problem. To diagnose this I would need to watch scan tool readings while driving the vehicle to see what sensors are showing at the point of failure. Things to watch are shift solonoids to see if they are being commanded to switch gears. If they are cycling on and off during the faliure then the trans is doing exactly what it is told to based on sensor inputs. At this point monitering input sensors would be required to determine which is sending an incorrect signal.

Now if the solonoids are NOT cycling when the trans is shifting in and out of gear then you have some sort of mechanical issue. Could be debris in the valve body, sticking solonoid, poor ground to a solonoid something along those lines.