Code U0057 indicates an open circuit detected on the vehicle's Communication Bus D network. This break in continuity prevents control modules from exchanging data required for normal operation. It is typically a wiring or connection issue rather than an internal computer failure.
Physical damage to the wire such as chafing, cuts, or rodent damage is the most common cause of network open codes.
Moisture intrusion or vibration can cause pins to corrode or back out, breaking the communication path.
If the modules on Bus D lose power due to a blown fuse, the network will appear open to the scanning tool.
A non-PCM module connected to this bus may have failed internally and is dragging down or blocking communication.
The central hub that routes messages between different vehicle networks may have developed an internal fault.
While possible, PCM failure is rare for this code and should only be considered after all wiring and other modules are ruled out.
Rarely. Most U0057 cases are caused by wiring breaks or connector issues, not internal module failure. Replacing the PCM without diagnosing the wiring is usually unnecessary.
No. Communication failures can disable safety systems and cause unpredictable vehicle behavior.
When one bus fails, all modules on that network lose communication, triggering multiple fault codes across different systems.
No. The specific location and function of Bus D vary by manufacturer and require specific wiring diagrams to locate.