1997 Breeze Temperature Sensor

I have a 1997 Plymouth Breeze that has been exhibiting some strange behavoir. It has been doing two things:

1. When I am sitting at idle in park, the engine typically idels around 800 RPM. Recently, as I am sitting in park, the idle will jump up to around 1200 RPM, then come back down to 800, then a while later back up to 1200. No defined interval. It seems random.

2. As I have been driving, the car will shift out of overdrive, run for a bit, then back into overdrive.

I think there is an interconnect such that when the car is cold, the idle is set higher and the trans is not allowed to shift into overdrive.

So my question: Is there a temperature sensor/switch to tell the computer when the engine is warmed up enough to allow the idle to come down and allow the car to shift into overdrive? I suspect that may be the problem, but I have not had a lot of luck locating such a device.

Any help would be appriciated. It appears there is a lot of knowledge on this forum.

Thanks

John


This problem ended up being the Throttle Position Sensor which eventually failed and dumped the OBD code saying the same. I changed it and the new Throttle Position Sensor I got eneded up being bad intermittently. Unfortunatley, I did not realize this right away. Figured it out this last weekend after buying a sensor from a junk yard car and swapping it out. Just thought I would update this so anyone else reading this in the future with a similiar issue may have another clue. Good luck.