There is a problem with the Overdrive. Seek professional help.
If the check engine light is blinking that indicates an engine cylinder misfire has been detected
Problem with the Overdrive system or the Transmission.
Commonly, the OD blinking and subsequent CEL are due to the tranny overheating. Most common on the 4 cylinder (AT) models. OD light blinking implies the tranny is overheating. the CEL appears when the tranny is significantly overheating. Frequent fluid changes and an auxillary tranny cooler can help extend the life. It appears that the transmission on the 4 cylinder is simply undersized.
It probably means that one of your head or tail lights is about to go out. I have a Ford Taurus and my right blinker started blinking very quickly and within a week, my right headlight was out.
If your check engine light is blinking with the engine running that is indicating a misfire - get your vehicle scanned for any trouble codes to diagnose and then repair the problem
The computer that controls the component cannot do what it wants to do so it signals you to give it attention get it diagnosied by an ASE trained experianced tech
Blinking red light signifies alertness or danger.
If your check engine light blinks with the engine running it means that a misfire has been detected . Your F150 needs to be scanned for trouble codes in order to diagnose which cylinder or cylinders are misfiring and then repaired
If the check engine light is blinking with the engine running , a spark plug misfire has been detected - get it scanned for trouble codes in order to diagnose and then repair the problem as soon as possible . If you don't , and continue driving with the check engine light blinking , you risk damaging your catalytic converter
A malfunction has been detected if the O D / OFF light is blinking
Stop. Treat the blinking red light as a stop sign.