Code U0443 indicates that a module on the vehicle's communication network is receiving data from Body Control Module B that is logically incorrect or out of the expected range. Unlike a total loss of communication, the modules are talking, but the information being sent is invalid.
The module itself has an internal hardware or logic fault causing it to broadcast corrupted data.
Chafed, pinched, or corroded wires in the communication network can introduce signal noise or interference.
A failing battery or unstable charging system can cause modules to operate erratically and send invalid data packets.
Software bugs in the BCM-B may cause communication errors that are resolved through a manufacturer firmware update.
The receiving module (such as the PCM) is misinterpreting valid data, though this is rare.
No. U0443 means the PCM is reporting that it is receiving bad data from another source. The fault is almost always located within the BCM-B or the wiring connecting it to the network.
Yes, poor grounding of the Body Control Module can cause voltage offsets that result in invalid data transmission.
Generally, no. U-codes typically affect convenience and body electronics rather than the primary engine combustion process, though some safety systems may be disabled.