When your Ford Fusion’s OBD port is on the fritz, it’s almost always an indication of a blown fuse.

Before you mess with the fuses, you must shut down the engine and disconnect the car battery. You can get a nasty shock, or worse, if you’re not careful. So please be careful!

This is where you should consult your car’s manual—specifically the fuse chart—to see which fuses should be checked. But fuse F18 in the smart junction box is usually a safe place to begin your search.

Checking a fuse is pretty straightforward. After carefully extracting the fuse with pliers or fuse pullers, hold the fuse up to the light and look through the clear plastic bit for the little metal wire inside. If that wire is broken, the fuse is blown and needs to be replaced.

If the fuses look fine, you should check the OBD port for physical damage. It’s a rare issue, but some Ford Fusion owners have reported damage or unusual wear on their OBD ports, especially on older models. It’s worth grabbing a flashlight and looking, though again, chances are this will be a blown fuse.

Once your OBD scanner is up and running, you may want to check out our brief guide explaining how to read your car’s OBD codes. A lot of that might just be refresher for you if you’ve used an OBD-II scanner before, but it never hurts to review!

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