A Audi A8L car with a distance of about 57 thousand KM. User reflection: the auto adaptive speed cruise can not use fault diagnosis: (1) the fault code is detected by VAS5052: ACC angle deviation can not be used, and the correction is required. Correction by prompt, adjustment in correction, VAS5052 prompt to turn left to turn the screw (2 in Figure 1) to 1.5 circles, and then to turn right turn to adjust the screw 1 circles for a moment, so come and go back and forth more than 10 times to determine the correct position of the radar sensor, correcting the past data is wrong. (2) several repeated corrections can not be completed. Reanalyze all the maintenance data about ACC and see the final introduction of the maintenance data: if the vehicle has a crash, the replacement of the frame in the front bar needs to be corrected by ACC. (3) at this point, we immediately checked the vehicle and found a slight bruise on the left front bar. We decided to check the front bar and found that the screw was loose. Reinstall and fix it for correction and troubleshooting. Troubleshooting: fixed adjustment screws to correct troubleshooting.