I have a 1996 (80k mi.) Ford Contour, 4cyl, 2.0L with CD4E automatic transaxle. The O/D Off light began blinking while driving on the highway, and the tranaxle downshifted to 3rd gear. The check engine code was P0715 indicating a faulty TSS sensor or circuit. I replaced the sensor, but this did not did not solve the problem. The O/D Off light continues to blink, the car shifts roughly between gears 1-2-3, and the 4th gear is locked out. Should I immediately suspect the wiring back to the PCM, or is there a mechanical condition that could cause this code to be triggered? The code indicates a >15 mph vehicle speed with a <60 rpm transmission shaft speed. Next step is to check harness wiring resistance. Except for some exposed sensor wires, most visible harness wires have intact insulation. Should I be looking elsewhere for the cause of this code?