The Throttle Position Sensor

The tranny repair bill did get paid off six months after the service was done, and I thought I was free and clear to drive without worry.  However, at 147000 miles the transmission did seem to fail again.  On April 14, 2003 I was on I-26 eastbound, driving back to my place after visiting my friend at his place on the lake.  Coming up on the city limits, I used the 'coast' button on my cruise control to slow the car down.  I watched the RPMs drop to right at 1000 and felt the car gradually slow down.  'Nice and smooth' I thought, right before the transmission kicked back to a lower gear somewhere around 65 MPH, tossing me into my steering wheel and giving me a few dandy bruises on my chest.

Immediately after that happened, the tranny went back into the proper gear and I very gently drove the car to my office since it was closer than my condo.  When I came to a stop at a red light at the end of an offramp, the engine idle became very erratic and the HOLD light flashed twice.  Quite thankful that I had my extended warranty, I parked the car and opened the hood.  Pulling out the dipstick for the transmission fluid, I saw that while the levels were fine, the usually pinkish fluid had a brown tinge to it.  Buttoning things up, I went into the office and made a few phone calls.  Ten minutes later I got back into my car and started it up.

To my surprise, the thing purred like a kitten.  When I put it into gear it drove away just fine, and I made it home without incident.  The next morning I took the car back to Mr. Transmission and had them look at it.  They agreed that there was something amiss and took it in for an examination.  Three hours later they called with the results.  The computer had logged an error with the TPS (Throttle Position Sensor), which had caused the errant kickback and had also accounted for some sloppy acceleration that I'd been experiencing over the past eight months.