Dangerous A/T Shifting Prob. HELP!

[DanZemke]

RE: 91 talon TSi, auto.... OK - when the car is warm (about 15 mins of good driving) I could be on the highway, lets say at 60 MPH, then all of a sudden, my car decides it doesnt want to be in OD anymore, and might shift to second, or first, then third, or whatever, then it may quit and act normal, or it may stay in like second! So the engine revs way up and when i pull over, as i slow down it automatically downshifts into first, and then stays in first as i start off again. Sometimes if i get mad and just drive it it might shift back to OD and all is fine for awhile. My fluid is good, newer filter, tranny rebuilt 30,000 miles ago. BUT those miles were put on in 5+ years, (i dont drive it much). It doesnt do it in the winter, but in the summer it does it right away. So its temp related somehow. My guess is a OD switch somewhere? Can someone help me please? I have many people baffled by this. Thanks for the help........ Dan in MN

[doug]

Have you upgraded your end clutch with the Alto kit?

[tsi91at]

Are you getting any CELs?? You may be having TCU issues. Keep in mind, they have capacitors as does the ECU. And we all know temp changes effect caps . Try pulling the codes (if any) from the TCU.

Same as pulling codes for ECU except use Pin 10 rather than 1.

Check for broken wires around and going into the tranny. It may be the End clutch or seals, but that is goofy behavior. Leads me to think electrical.

Charles
http://www.plymouthlaser.com
http://groups.yahoo.com/group/AT-DSM/files/Helpful%20Trans%20Pics/alto2.jpg

[Blackboost]

Check the TCU like the member above mentioned. Also that problem could be related to bad "shift solenoids" on the tranny valve body.

[lefevredc]

DanZ
Also check to see if your speedo reading drops out. Not sure if it's fed from the TCU like my '95, but that would be another indicator of a bad TCU.
All the symptoms you're naming sound like what I just went through. The TCU was the culprit.