Airbags

B0050 — Driver Seatbelt Sensor Circuit Fault

Severity: medium Safe to drive

What B0050 means

The restraint or body control module monitors the driver seatbelt buckle through a switch or sensor in the latch. B0050 is stored when that signal or its circuit is out of range, open, shorted or otherwise implausible. Buckle status is used for the belt reminder and to help decide how the pretensioner and airbag deploy.

Symptoms

  • Seatbelt warning light on or flashing with the belt buckled
  • Constant chime even though the belt is fastened
  • Airbag (SRS) warning light on
  • No change in engine or transmission performance

Possible causes

  1. Faulty seatbelt buckle sensor
  2. Damaged, corroded or loose connector or wiring under the driver seat
  3. Body control module (BCM) or SRS module fault or communication error
  4. Power or ground problem in the sensor circuit
  5. Dirt or spilled liquid in the buckle

How to diagnose

  1. Scan all modules including SRS, note freeze-frame data and see if the code returns after clearing
  2. Inspect the buckle and make sure the tongue latches fully and the slot is clean
  3. Check the connector under the driver seat for corrosion, bent pins or a loose lock
  4. Wiggle the harness near the buckle while watching sensor data on the scan tool
  5. Measure resistance and voltage in the sensor circuit per the factory wiring diagram
  6. Verify power, ground and related fuses
  7. If wiring is good, test or evaluate the SRS or BCM

Common fixes

  • Replace the seatbelt buckle with sensor
  • Repair or replace damaged wiring and connectors
  • Clean the connector contacts and the buckle
  • Reprogram or replace the BCM or SRS module if confirmed faulty

Questions and answers

What does B0050 mean?

It indicates a fault in the driver seatbelt sensor circuit. The control module is getting a bad signal from the buckle sensor or none at all.

Is it safe to drive with B0050?

The car will drive normally, but the airbag and pretensioner may not work as intended. Get it checked soon.

Can I just clear the code?

You can, but it will return if the cause is still there. Check the buckle, the connector and the wiring under the seat first.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.