Setting of "reset function" of car lights: When the engine is turned off, the key is pulled out, and the driver's door is opened, the low beam light, the front and rear width indicator light, the license plate light and the exterior rearview mirror light should be lit. This is the so-called "home function". If there is no such function, it can be set by modifying the code of the control unit. The operation method is as follows (take Shanghai Volkswagen Tiguan as an example): (1) Connect the scan tool V.A.S505X and select the vehicle self-diagnosis function. (2) Select the address code "09" (BCM). (3) Select the "coding" function. (4) Select a long code. (5) Select bytel2 and change the original "10" to "14". (6) Select bytel7 bytes and change the original "75" to "55". (7) Press the accept key to save. The way to check whether the above settings are successful is to turn off the engine, take out the key and turn the left steering column switch inward. If the low beam lights, front and rear width lights, license plate lights and lighting lights on the exterior rearview mirror are all on at this time, the lights will be on. Home page function set successfully.