This code U1025 is related with the network of the car engine and it is very informative but short. Getting the real meaning of the code is not possible without following the real meaning of the car engine manual. You will get that meaning in the car engine manual and car manual. Do not use common automobile information for solving the car engine problem. Read the manual of the car where you will get all necessary information. Do not try to follow the car engine with false information. The false information is not helpful for solving the car engine problem.