Q: Motion sensors for accident avoidance gives false positives

asked by on March 19, 2018

My Ford C-Max Hybrid’s motion sensors are messed up in a weird way. Ford says there is nothing wrong. They work fine when driving/parking, however, they also send LOTS AND LOTS of false positives, mostly when stopping at a light or stop sign. Very frequently there is NO ONE AND NOTHING around me when it goes all the way to a “solid beep” as if i’m about to hit something when i’m at a dead stop! as in i will completely stop, then it will start beeping continually. i have to put it in park at nearly every light or long stop to avoid losing my mind. As i said, the Ford guy had someone walk around the car, and the sensors worked fine, so he concluded i was crazy. They also tell me they cannot disable the sensors. HELP!

My car has 48000 miles.
My car has an automatic transmission.

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Be sure all sensor elements are clean and unobstructed. According to surveying carried out by "Consumer Reports", the Ford system is among the more reliable in the industry so, based on your description, the accident avoidance system is malfunctioning. The "test" that you describe at the dealership doesn’t match what is documented as required diagnostics on the many pages of instructions in the Ford Service Manual to troubleshoot the accident avoidance system. There is no need to disable the sensors; what you need is a mechanic who will implement the required diagnostic. The recommended service to do that is an electrical diagnostic. If you request that service, the responding certified mechanic will get this diagnosed and resolved, right at your location. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.

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