Where is the ford focus parking sensor module located?

The parking sensor module (PSM) for Your Ford Focus is going to be located in the trunk/cargo area of Your vehicle. It's a small square plastic component, that says "REAR PARKING AID MODULE" on it, and will have the part number F1ET-15K866-AG. To access it, remove the cover on the driver's side --- You'll see there's a very small squarish panel there, on the back of the seat --- and You should immediately see it. It's only clipped into place, with a large purple wire terminating in a molex connector mating it to the system computer. Disconnect that cable, unclip the tabs, and gently pull it towards You out of the alcove. If You're looking to save a bit of money on costs replacing, You can usually find used PSMs on eBay for around $44.