Faulty seat belt buckle sensor (integrated into the buckle assembly); Damaged or chafed wiring harness under the seat or along the floor; Corroded or loose electrical connector at the sensor or BCM; Failed occupant detection sensor or weight sensor in the seat cushion; BCM software glitch or internal fault; Aftermarket seat covers or objects interfering with the sensor; Liquid spill or physical damage to the seat belt latch mechanism

DTC codes / B00xx · Airbags, seats, doors, lights and comfort systems / B0055

B0055Second Row Right Seat Belt Sensor

Q: What does code B0055 mean?

Second Row Right Seat Belt Sensor. B0055 indicates that the body control module (BCM) or occupant classification system has detected a fault in the second row right seat belt sensor circuit, which typically monitors buckle status and belt tension. The computer sets this code when the sensor signal voltage or resistance falls outside the expected range, or when the circuit is open or shorted.

B0055 indicates that the body control module (BCM) or occupant classification system has detected a fault in the second row right seat belt sensor circuit, which typically monitors buckle status and belt tension. The computer sets this code when the sensor signal voltage or resistance falls outside the expected range, or when the circuit is open or shorted.

SystemBody

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

Seat belt warning light illuminated on the dashboard
Chime or reminder that does not stop even when the belt is buckled
Airbag warning light may also be on if the system disables the passenger restraint
Often no symptoms besides the warning light
Inconsistent operation of the seat belt reminder for that seating position
Remote start or other features that rely on seat occupancy may be affected

Common causes, most likely first

Faulty seat belt buckle sensor (integrated into the buckle assembly)
Damaged or chafed wiring harness under the seat or along the floor
Corroded or loose electrical connector at the sensor or BCM
Failed occupant detection sensor or weight sensor in the seat cushion
BCM software glitch or internal fault
Aftermarket seat covers or objects interfering with the sensor
Liquid spill or physical damage to the seat belt latch mechanism

How to diagnose and fix it

Inspect the seat belt buckle and surrounding area for debris, damage, or aftermarket accessories that could interfere with the sensor
Check the wiring harness and connectors under the second row right seat for chafing, corrosion, or loose pins
Use a scan tool to view live data for the seat belt sensor and confirm the signal changes when the belt is buckled and unbuckled
Measure resistance and voltage at the sensor connector and compare to manufacturer specifications
If the sensor signal is erratic or out of range, replace the seat belt buckle assembly
If the circuit tests good but the code persists, check for BCM software updates or diagnose the BCM
Clear the code and verify the repair by cycling the ignition and confirming the warning light stays off

Seat belt sensor faults that fool technicians

A common oversight is replacing the seat belt buckle when the real problem is a corroded connector under the seat that causes high resistance and sets the code.
The second row right seat belt sensor often shares a ground with other sensors, so a bad ground can set multiple codes and mislead diagnosis.
After a collision repair, the seat belt pretensioner may have deployed and the buckle sensor may be damaged, but the code can appear only after the battery is reconnected.
Some vehicles use a hall-effect sensor in the buckle that can be tested with a magnet; a quick magnet test can confirm sensor operation without a scan tool.
The code may be set by a low battery or voltage spike, so always clear the code and verify it does not return before replacing parts.

Can I keep driving with B0055?

The vehicle remains safe to drive because the seat belt itself still functions, but the airbag system may be affected if the fault disables the passenger restraint, so have it diagnosed soon. Avoid ignoring the warning light for extended periods, as the restraint system may not deploy correctly in a crash.

Tools that help

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