My wife has a 1999 Expedition, the "OFF" light flashes on the overdrive on it's own. The overdrive works and when it is in overdrive, if you depress the button, the transmission comes out of overdrive. When you depress it again, it shifts into overdrive. This just started lastnight, I checked for codes lastnight and the computer is clear. She says that if now feels like the brakes are set, I drove it and it feels OK to me. Can anyone out there lead me in the right direction so I can fix this.

Thanks
Terry

 

Make certain your scan tool is capable of pulling manufacturer-specific codes. the low-end code readers/scanners cannot. Consult your owner's manual to see what the capabilities of your device are.

Really need the fault codes set by the PCM to see what is going on.

If possible, you may need to keep from turning the truck off and to connect the scanner and read codes with the engine still running and the OD light flashing.

Steve