Hey guys, 2003 caravan 3.3L Problem- Intermittently On first start up and sitting at stop lights , it feels like someone is shifting in and out of gear. like from neutral to drive. Also when you put it in gear the speedo needle bounces around between 15-30 mph when your not moving. In park it will sit at zero. When you unplug the output speed sensor it will sit zero in gear. Also after driving it for while , it will intermittently get stuck in first gear. The last time this happened , I shut it off the restarted and it shifted fine again. It shifts fine otherwise. Check engine light is on. I've changed fluid with ATF 4 and filter. Replaced both input and output speed sensors. Got ahold of 2 used tranny computers same year and tried em both and it acted the same on all 3. Any advise would be helpful. Thanks

 

Did you have the code(s) read yet. If not, and it's a P0700, then you will need to have the TCM codes read with a reader that can do that. Also have the CVIs read as well.
About the only lesser expensive thing left is the solenoid, but you should get the above things done first before hanging on any more parts.

 

cv2003,
No I haven't had the codes read yet. I was kind of leaning that way as the next thing to do. So I'll probably take it in to have it put on a scan tool and go from there. Thanks for your advice

 

I would first by checking the wires going to the output sensor, see if you have battery acid that shorting the wires together. And have the transmission module scan for codes.

 

The battery cable ends were pretty corroded. I cleaned them up the other day. I will check those wires tomorrow. Thanks

 

Alternator.. Took it into a Tranny shop to have the codes read. they said they had seen this on about a half dozen Chryslers where the defective alternator back feeds the computer system. Causing a 12 volt spike in the 5 volt computer system intermittently which in turn caused the computer to receive false readings from sensors like the speed sensors. These alternators don't have voltage regulators built into them, the voltage is regulated by the computer. So I brought it home swapped out the alternator and it shifts perfect and the speedo problem resolved as well. Just wanted to get back and let everyone know what took care of it. Thanks for the replies I did receive..

 

Thank you for the update.