One more down and dirty tip for you DIYers. I don't know whyI keep posting this stuff, probably costing myself a new bike.

Place ignition in RUN position WITH ENGINE OFF!!!, put selector in reverse and set parking brake or if you are afraid your brake cables may be sticky from lack of use CHOCK WHEELS SECURELY, get down on your hands and knees and put your ear to each sensor. Working sensors make a high frequency ticking sound that is easily heard. Any sensor not making noise is either suspect or wiring damage is disrupting power or signal. If you find one not working simply swap sensors hole to hole and see if the sensor works in a different position. This is easy on X-Types due to location but much more difficult on other models. If none are making noise check fuses to module and look for water ingress into trunk spare tire well where module is located. Harness damage and corossion is common on the X-Type due to the exposed nature of the sensors, hell, harness damage is common on all models because the other models with sensors mounted in the bumper have their harnesses damaged by low speed impacts to the bumper. I know what you're thinking "how do you get impacts to the bumper if they have park aid" but it happens all the time and a parked car is just as susceptible to a bumper ding as a moving one.