U0001 /B020wgm5i U00021 2025 Manual. This fault code can cause issues with the vehicle’s performance and should be addressed immediately. These errors can be caused by a variety of factors,.
The can bus is a computer network that connects all electronic control units (ecus) in a vehicle. The u0001 code occurs when your car fails to receive an automated message confirming that the can bus is transmitting information correctly.