B0055

Code

Generic B — Body

Second Row Right Seat Belt Sensor

Brand: Generic

Type: B — Body

Views: UK: 14 EN: 44 RU: 22

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty second-row right seat belt buckle switch / sensor
Broken, shorted or disconnected wiring between buckle and restraint/occupant module
Corroded or loose connector at the buckle or module
Water intrusion or contamination in the seat or connector
Faulty occupant classification module (OCM) or airbag/SRS control module
Aftermarket seat cover or debris preventing proper switch operation

Symptoms

Airbag / SRS warning lamp illuminated
Seat belt warning light or chime behaves incorrectly for the second-row right seat
Occupant detection/airbag enable status incorrect for that seating position
Possible inability to register a buckle as fastened (chime continues)
Possible stored diagnostic trouble codes related to other restraint components

What to check

Read and record all stored SRS/seat belt related codes and freeze frame data with a scan tool
Check live data/BCM or occupant module inputs while buckling/unbuckling the seat belt
Visually inspect seat belt buckle, harness routing, connectors and for signs of water/damage
Wiggle test harness and connectors while monitoring the live data for intermittent faults
Measure voltages, continuity and resistance at the buckle connector and at the module connector
Verify proper power and ground to the occupant/airbag module and to the circuit

Signal parameters

Buckled vs unbuckled: buckle switch typically presents as closed (low resistance) when latched and open (high/infinite resistance) when unlatched
Voltage-based circuits: expected logic-level signal typically near 0 V (ground) or near supply/reference (commonly ~5 V) — vehicle-specific values required
Continuity: closed circuit typically low ohms (near 0–2 Ω); open circuit shows OL/infinite
Intermittent faults may show rapid toggling between the two states when monitoring live data

Diagnostic algorithm

Retrieve B0055 and any related codes with a scan tool; note freeze frame and live data.
Follow vehicle manufacturer's SRS safety procedure before touching restraints (disable battery and wait the recommended time).
Visually inspect the right second-row buckle, harness routing, and connectors for damage, corrosion or contamination.
With connector accessible, monitor the buckle circuit signal on the scan tool while buckling and unbuckling to confirm behavior.
Perform a wiggle test on the harness and connector while watching live data to detect intermittent opens/shorts.
Unplug the buckle connector and measure continuity/resistance across the switch terminals while actuating the buckle — verify open/closed behavior.
Backprobe the harness at the module connector to verify reference voltage/pull-up and signal voltage transitions (compare to vehicle-specific values).
Check continuity between the buckle connector and the occupant/airbag module to rule out harness breaks; inspect grounds.
If harness and connector are OK but signal is still incorrect, swap or bench-test the buckle sensor if a known-good part is available.
If replacement sensor fixes the issue, clear codes and verify no reoccurrence. If problem persists, test/replace the occupant classification or SRS control module per manufacturer procedures and program if required.

Likely causes

Open or intermittent wiring in the buckle harness (most common)
Failed buckle switch (mechanical wear or internal corrosion)
Connector corrosion or pin pushed out at the buckle
Water or foreign matter in the buckle assembly
Module input circuit fault or module software/hardware failure (less common)

Fault status

⚠️ Status

B0055 — Second row right seat belt buckle/sensor circuit fault detected: open, short, intermittent or implausible signal. Check buckle switch, wiring and connectors; replace or repair as required.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours