B0050 indicates a fault in the circuit for the driver seat belt sensor, which tells the SRS/airbag system whether the driver seat belt is buckled. The airbag control module uses this input to decide airbag deployment strategy, so the code stores when the signal is missing, implausible, or shorted/open. It is a body-system (B-series) code and will usually illuminate the airbag warning lamp.
The switch or hall-effect sensor inside the driver buckle assembly is the component most often at fault, because it cycles every time the belt is buckled and unbuckled and can wear or stick internally.
Wires running between the buckle and the SRS module can fatigue from seat movement, door closure vibration, or pinch points under the seat, causing opens, shorts, or intermittent contact.
The connector under or beside the seat can collect moisture, develop corrosion, or work loose from seat adjustment movement, disturbing the sensor signal.
Spilled liquids, dirt, or small objects inside the buckle can prevent the internal switch from moving fully, making the system read an incorrect belt status.
This is uncommon; the module itself rarely fails for this single code and should only be suspected after the sensor, wiring, and connectors have been ruled out.
The vehicle will usually drive normally, but the airbag system may not deploy optimally in a crash because it does not know the driver belt status. It should be diagnosed and repaired promptly.
Clearing the code may turn off the light temporarily, but if the underlying sensor or wiring fault remains, the light and code will return as soon as the system runs its self-test again.
Usually no. The failed component is most often the buckle switch/sensor, a connector, or wiring. Replacing the SRS module is rarely the correct fix for this code and should only be considered after those items are verified good.
Not necessarily. The code refers to the electrical sensor circuit that detects buckle status, not the webbing or retractor. The belt may look fine while the sensor circuit is faulty.