OBD-II code U0517 means a control module on the vehicle network has received invalid or implausible data from Door Switch B (the specific door assigned as 'B' by the manufacturer, typically passenger or rear). The fault is in the sending switch, its circuit, or the network itself, not in the module that stored the code. It is part of the U-code family, which covers communication errors between modules rather than individual sensor failures.
The switch itself has internal wear, contamination, or mechanical failure and is sending out-of-range or stuck signals on the network.
Corroded, bent, or loose pins in the door switch harness, or broken/chafed wires between the switch and the body module, are a very common source of invalid data.
Low voltage, high resistance, or a missing ground at the door switch can cause it to transmit erratic data that the receiving module flags as invalid.
A short, open, or excessive resistance on the communication circuit, or electromagnetic interference from another fault, can corrupt the door switch message.
In some cases a software bug or failed reflash in the door module or the receiving module causes legitimate switch data to be interpreted as invalid.
Rare. The module that stored U0517 has internal circuitry failure causing it to misread good data; only consider after every other cause has been ruled out.
Almost never. U0517 is a network communication code that points to the door switch or its circuit as the source of bad data. The module that stored the code is usually just the messenger. Replacing it is an expensive guess that rarely resolves the issue and should only be considered after the switch, wiring, power, ground, and network have all been verified good.
Generally yes, the vehicle will usually remain drivable. However, features tied to door status such as interior lights, alarm, auto-lock, and door ajar warnings may not work correctly until the fault is repaired.
The assignment is set by the manufacturer and is not standardized. It commonly refers to the passenger or a rear door, but the only reliable way to know is to consult the wiring diagram or service information for the specific vehicle.
Sometimes. If the root cause is corrosion, moisture ingress, or a loose pin, cleaning the connector, applying dielectric grease, and clearing the code can resolve it. If the switch itself is electrically failed, the code will typically return.