A 2011 mile TOYOTA highland with a mileage of about 54 thousand km. Customer response: the vehicle has been running on uneven roads, and the roof has been badly sounded. It has been more than a week since the car came into operation and required thorough solution. When testing with customers, when the vehicle is running on a slightly uneven road, the rear part of the skylight will emit a very big "Zheng Mun..." The noise is eliminated when the sunroof shading board closes or hands up slightly against the rear roof of the skylight. The causes of failure are as follows: (1) the loosening of the skyframe skeleton bolts; secondly, the gap between the skylight frame and the roof gap; 3. Fault diagnosis: check the location of the fault and use vibration method to vibrate skylight glass. The tremor noise can also emit "Zheng Mun..." when closing the door. When the sun shading board is closed, the sky window glass is vibrated again, and the noise of the noise is almost eliminated, indicating that the problem appears in the sunshade board and the related parts of the slide rail. Further determine the fault location, open the skylight sunshade board, hold back the rear window of the skylight by hand to about 30cm, shake the skylight again, remove the noise, and judge that the abnormal sound should be the reinforcement part of the back of the skylight skeleton. Disassemble the slipping skylight seal, the right two armrest and the B column decorating plate to make the roof sink a little, observe the slip rail and the rear stiffeners on the sides of the skylight, and the rivets at both ends of the reinforcement are not loose. The sliding sky window shading board observed the gap between the sunshade board and the sky window slide rail and the rear reinforcement, and found the skylight. The gap between the front end and the rear end of the slide rail is not consistent and the rear end is large. There is a certain gap between the sun shading board and the backend of the skylight frame. It is doubted that the sunshade board in the sky window is beating in the slider. Gently hold the rear reinforcement of the skylight frame with your hands, shake the skylight glass again, eliminate the abnormal sound, release your hand, and the abnormal sound appears again. To find the vibration parts of the noise, we put a 3M glue on a 3mm thick sponge foam on the back of the back of the skylight skeleton, so that the sun shading plate is just passed, that is, to prevent the vibration of the vibrating parts and to reduce the time of the disassembly of the roof. Troubleshooting the test car. Fault summary: in the maintenance of vibration noise, we must understand the mechanism and vibration transmission of the fault, find the fault location, we can solve the problem quickly and accurately.