I have a 99 F-150 4 by 4 auto trans. im having a problem when i slow down almost to a stop the overdrive off light starts blinking and it downshifts hard. the OD light button is on the shifter which is on the steering column.Does anybody know the solution?

 

You need to have the codes read. The flashing O/D light indicates a trouble code has been set. You may need a higher end scan tool than what the auto parts house uses. Theirs may be able to read them because the trans codes are stored in the PCM. Post the exact code number back and we can help.