The network problem of the engine is easy to solve and the engine U1236 Code gives you information about the car engine problem what you can use for solving the car engine. Do not allow any false meaning for solving the car engine. However, you should not fix the car by an immature automobile engineer or by yourself if you have no idea for solving the car engine. You should not drive the car if the problem of the car engine is unsolved. You should test the car engine after solving the car engine problem. After confirming that everything is ok, you can accept the car.