Body, generic

B0058 Third Row Right Seat Belt Sensor

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B0058 is the J2012 code for the buckle sensor at the right seat of the third row. The sensor reports a latched or free belt to the module that runs the rear belt display, which FMVSS 208 S7.5(c) makes mandatory for every rear seat from September 2028. Fold-flat third rows and access from the right-hand sliding door put the lead under strain. No carmaker documents B0058 publicly with this meaning. Older GM modules again differ: on the 2006 Saab 9-5 B0058 means an open passenger pretensioner loop, with more than 4.5 ± 0.2 ohms for 2 seconds, while the Saab 9-3 also knows a high-resistance variant. GM bulletin 14609 for 2004-09 Colorado and Canyon extended cabs covers B0058 among the pretensioner codes caused by broken rear door wires.

Likely causes

Buckle lead of the right third-row seat damaged by folding or loading
Older GM/Saab module: open passenger pretensioner loop, e.g. broken rear door wire
Faulty sensor in the right third-row buckle

Symptoms

  • Airbag warning lamp on
  • Depending on the module: right third-row seat shown wrongly, or passenger pretensioner may not fire
  • Safety note: buckle and pretensioner plugs carry firing circuits nearby; only unplug them with the battery disconnected and the wait time observed

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–600
Time0.5–3 h

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

Parts involved

seat belt buckle switchsrs seat wiringpassenger seatbelt pretensionersrs control module

Related codes

B0056B0057B0078

References: law.cornell.edu, saabwisonline.com, saabwisonline.com, static.nhtsa.gov.