Ford focus 2015 SE electrical issues? Possible ECU failure?

So… This is the 2nd time this has happened:

Driving my car and all of a sudden, “hillside assist not available” alert appears on the dash, my left turn signal won’t turn off, I drive the car home, turn it off, and now it won’t start, and keeps giving me a “No Key Detected” error.

The OBD port also won’t start my scanner? Lack of power?

I brought it in to the ford dealership and they couldn’t figure out what was wrong with it other than a bad battery. Replaced it and nothing was wrong up until today. (3 days later)

Someone else posted the exact same issue for their
exact same Ford Focus, same year and everything another mechanic chimed in saying it sounded like ECU failure?

Any help would be really appreciated.


The alternator might have conked out. Ask you mechanic to check that also.

Or if you knowhow to work a DVM, measure the battery voltage before the first start of the day. It should be about 12.6 volts. Then immdiately after starting the engine, 13.5 - 15.5 volts.

Definitely suspect the alternator if you car has been used to jump start other cars, or it has obtained jump starts.

If the vehicle has under 80,000 miles, it may be covered under the EPA mandated warranty.

performance warranty

Most people know about the original manufacturer’s warranty, also called the bumper-to-bumper warranty, that covers repairs to nearly everything on the vehicle excluding normal wear and tear. The Federal Emissions Warranty, however, gives you added benefits on top of that coverage. If the vehicle fails an emissions test during the vehicle’s first 2 years/24,000 miles (8 years/80,000 miles for specified major components), the manufacturer must make repairs or modifications necessary to allow the vehicle to pass. Specified major emission control components are covered for and include only the catalytic converters, the electronic emissions control unit or computer (ECU), and the onboard emissions diagnostic (OBD) device or computer. This applies even if there are no mechanical defects with the vehicle. It is different from the Design and Defect Warranty.

Take it back in.


This is completely uneducated and random, but try changing the Fob battery.

It has been my experience that “Your ecm is bad” usually means “I have no clue what is wrong with your car so I will blame the ecm.”

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My vote is for a bad BCM. Being around the auto world for more than a few years I can say that in my lifetime I’ve only seen 3 bad ECMs. One on a Volvo, one on a Subaru, and a reman Ford unit that had a fuel pump relay circuit fail a week after the install.
Have seen a number of them replaced on a futile WAG.

Those things work and hold up amazingly well considering the temperature swings and vibration they go through.