Body, generic

B0055 Second Row Right Seat Belt Sensor

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B0055 stands for the buckle sensor of the right seat in the second row, behind the front passenger and in vans often beside the sliding door. Where that seat is a removable captain's chair, a disconnect in the buckle lead is unavoidable; IEE points out in a patent that a wireless buckle sensor alone cannot tell the module whether the seat is fitted, so a missing signal may mean a fault or simply an empty floor. A seat refitted with its plug left open is therefore a common trigger. CTS supplies non-contact Hall buckle switches for such uses. The rear belt warning of FMVSS 208, section S7.5(c), applies to this seat for vehicles made after 1 September 2028. No carmaker documents B0055 publicly; the Mitsubishi passenger code B0052 is the nearest documented model.

Likely causes

Seat connector not engaged after the removable seat was refitted
Corroded buckle connector, e.g. from wet floor near the sliding door
Faulty sensor in the right rear buckle

Symptoms

  • Airbag or rear belt warning lamp on
  • Right rear seat shown wrongly or missing in the belt status display
  • Safety note: seat and buckle plugs under the seat lie near pretensioner and side airbag lines; only unplug them with the battery disconnected and the wait time observed

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–450
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

seat belt buckle switchsrs seat wiringsrs control module

Related codes

B0053B0054B0075

References: patents.google.com, ctscorp.com, law.cornell.edu, mitsubishitechinfo.com.