1999 Ford Taurus Keeps Flashing O/D Off Light

This has been happening for a while now. It usually occurs after being stopped or traveling at low speeds, the O/D Off light will start blinking, the speedometer will stop responding and the rpm’s will go all the way up to 5 or 6 (x1000) when I’m accelerating to 20mph. Stopping the car, putting it in park and turning it off/turning it back on usually fixes the problem but I was wondering if my transmission is about to die or if it’s a sensor. The car has no Overdrive button to toggle on/off.

Have a good independent transmission shop scan your transmission as soon as possible (not Aamco). The owner’s manual for these vehicles warns one to have the dealer check the transmission immediately when the problem occurs. A good independent shop, in my opinion, would be better.

My son had this problem occur on a 1999 Ford Windstar which has esesentially the same drivetrain. The vehicle stopped and he had a partial transmisison rebuild.

The flashing O/D light is telling you that the computer has picked up a problem in the transmission, you need to have the computer scanned for trouble codes. Post back here with the code/s and we can go from there.


Since you indicate that the speedometer stops working when this issue happens, I suspect that there is a good chance there is a problem with the VSS (Vehicle Speed Sensor). It could be the sensor itself, but since turning the car off then on restores operation, it is more likely to be something with the PCM electronics.