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DTC codes / B00xx · Airbags, seats, doors, lights and comfort systems / B0058

B0058Third Row Right Seat Belt Sensor

B0058 indicates that the body control module (BCM) or occupant classification system has detected a fault in the third row right seat belt sensor circuit, which typically monitors buckle status and belt tension. The computer sets this code when the sensor signal is out of range, intermittent, or missing entirely, preventing the system from reliably knowing whether the seat belt is buckled.

SystemBody
Code typeGeneric (all makes)
SeverityLow
Fix difficultyIntermediate
AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

  • Seat belt warning light stays illuminated or flashes even when the third row right belt is properly buckled
  • Audible chime continues after the belt is fastened, especially when a passenger sits in that seat
  • Airbag or supplemental restraint system (SRS) warning light may illuminate because the belt status affects deployment logic
  • Often no symptoms besides the warning light, with the belt functioning normally when latched
  • In some vehicles, remote start or other body functions may be inhibited until the fault is resolved
  • Inconsistent operation where the warning appears only over bumps or in cold weather

Common causes, most likely first

  1. Faulty seat belt buckle sensor or tensioner sensor internal failure
  2. Damaged or chafed wiring harness under the third row seat, often from cargo or seat movement
  3. Corroded or loose electrical connector at the buckle or under the seat
  4. Failed body control module (BCM) or occupant detection module not interpreting the sensor signal correctly
  5. Seat belt buckle mechanism jammed with debris or foreign material, preventing sensor actuation
  6. Aftermarket seat covers or accessories interfering with the buckle sensor travel

How to diagnose and fix it

  1. Inspect the third row right seat belt buckle and its connector for physical damage, debris, or corrosion, and clean or reseat as needed
  2. Use a scan tool to read live data for the seat belt sensor status while buckling and unbuckling the belt to confirm the signal changes
  3. Perform a wiggle test on the wiring harness and connector while watching live data to reveal intermittent opens or shorts
  4. Check continuity and resistance of the sensor circuit against the manufacturer's specification, repairing any damaged wires
  5. Substitute a known-good seat belt buckle sensor or simulate the correct resistance to verify the fault follows the sensor
  6. If the sensor and wiring test good, diagnose the BCM or occupant detection module for internal faults or software updates
  7. Clear the code and verify the repair by cycling the ignition and confirming the warning light stays off during a test drive

Why the belt light lies about a buckled belt

  • A common misdiagnosis is replacing the seat belt buckle when the real fault is a chafed wire under the third row seat where cargo or folding seats pinch the harness.
  • The sensor often reports a valid signal when tested statically, so the fault only appears during seat movement or vibration, making a live-data wiggle test essential.
  • Aftermarket seat covers or heavy cargo pressing on the third row seat can damage the sensor or its wiring, and the code may return until the cause is removed.
  • On some vehicles, the third row right belt sensor shares a ground or signal wire with the occupant detection system, so a fault there can set B0058 along with other body codes.
  • The code does not always mean the sensor is dead; a loose connector or a BCM software glitch can set it intermittently, and a software update may be the correct fix.

Can I keep driving with B0058?

The vehicle remains safe to drive because the seat belt still latches and restrains occupants mechanically, but the warning light and chime will continue and the airbag system may not optimize deployment for that seat. Avoid carrying passengers in the third row right seat until the fault is repaired, and do not ignore the light if it is accompanied by an airbag warning.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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