Two problems related to horn assembly have been reported for the 2018 Honda Odyssey. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2018 Honda Odyssey based on all problems reported for the 2018 Odyssey.
Vehicle was off in a parked state in my driveway. The electrical harness for the horn malfunctioned and the horn was audible for about 4 minutes. During which, the fuse for the horn was removed, though the horn did not stop being audible. After the four minutes, the horn cut off and the harness shorted out. Smoke was visible as well as the smell of burnt wire coming from the drivers side front headlight. Pulling of the fuse had no effect as the horn continued to be audible. The cause is unknown at this time and can potentially lead to a fire in the vehicles engine compartment. There was no one driving the vehicle at the time. Maintenance is preformed iaw the vehicles manual at an official Honda dealership.
Horn on 2018 Honda Odyssey (elite & touring trim levels) for sure. Horn is a single tone low note and is barely noticeable and woefully inadequate. Yesterday while traveling on a not very busy country road, I activated horn at about a dozen buzzards feasting on some roadkill in the roadway and had to come to an almost complete stop before they moved. They were more intimidated by presence of my vehicle than horn blaring at them. Sounds stupid, I know, but it emphasizes problem. Horn is almost entirely unnoticeable and does not get or attract attention, which makes it a definite safety concern. It does not "command" your attention and is not easily heard over ambient noises. Horn on my previous 2013 Odyssey was a dual tone horn and much louder and drew attention immediately. I seriously doubt the factory installed horn meets federal standards for decibel level. Not that it matters but it just sounds pitiful coming from an almost $50,000 fairly large vehicle. Honda has truly dropped the ball on this safety item and I believe it is enough of a concern to replace this lousy horn with a much louder dual tone horn at my own expense. Someone there should take a look at this issue. This issue comes into play at any time the horn is needed to attract attention or alert someone to any number of situations and needs to be corrected before someone gets hurt or killed.