Hello, am a newbie to this forum. I have read all recommedations, searched on this subject and checked the FAQs, without an answer.
I have a 97 LX 2.5L Duratec V6 ATX, 113K with a transmission problem.
About 10K ago the Check Engine light came on and O/D Off light started flashing while driving on the highway, and the car would no longer shift into overdrive, and also started shifting hard in lower gears. Once I stopped the car it seemed to reset sensors and the car would drive fine for awhile, then the problem would re-apear. Took it to a Ford dealer and got codes P0715 and P0174. They repaired a vacuum leak and changed the speed sensors, which ones I'm not sure as they didn't specify. Car ran fine until recently.
Now the Check Engine light came on and O/D Off light started flashing again while driving on the highway. Took it for a different Ford dealer (because I moved) and got codes P0715, P0733, P0734 with description: "TSS Sensor Code and 3-4 shift problem. Possible internal repair. Possible PCM damage." They only advised replacing the trans with a new one for $3400 "due to known problems with the Contour's electronic trans." But they stated that I could drive it a while without 4th gear.
So I took it to a to a local trans shop near where I worked, they got the same codes and advised first replacing the TSS sensor and see if this solved the problem. Then, without doing any repair, the problem stopped, and the trans shop said to wait until the problem came back.
Drove the car for another month, and during a rainy period the problem came back: Check Engine light came on and O/D Off light started flashing, wouldn't shift into 4th, sometimes would downshift into 2nd, back and forth, hard shifting intermittently. Then after 2 days, the car was running and shifting fine without any lights.
Now the shifting problem is back after driving the car for about 15 miles, but without any error lights, but shifting problems while driving at highway speeds and stop and go. After turning the car off and starting again, it would shift ok for a while, and the problem would start again.
I took it to a different trans shop (an not working near the old trans shop anymore), and they advised rebuilding the trans. I asked about the sensors, and they said based on their driving the vehicle they think the problem is internal. They said that the rebuild would cost $1400 and to include replacing all sensors would cost $1800, with a 6 month warranty. Seeing that the car is only worth about $2000 I'm not sure I want to go that route for only a 6 month warranty.
Based on a problem that is intermittent, it seems to me (automotively layman) that the trans problem is electronic and may be resolved by replacing a defective sensor without a complete rebuild, but the trans shop says that if a sensor is out, it is out, and the problem would then occur consistently.
I would appreciate some expert advice as to the repair route I should go. Thank you.
