B0053Second Row Left Seat Belt Sensor
- Generic OBD-II code · Body
- How the car detects it
- B0053 is the J2012 slot for the buckle sensor at the second row's left seat. Rear buckle sensors drive the rear belt reminder: for vehicles built from September 2028, FMVSS 208 S7.5(c) demands a start-up display of which rear belts are fastened or open and a warning when one is unlatched while driving. No carmaker documents B0053 with this meaning publicly; the closest documented case is Mitsubishi's passenger code B0052, set for an open, shorted or invalid buckle signal lasting 2 seconds. Older GM airbag modules give the number another meaning: the Saab 9-3 and the 2006 Saab 9-5 store B0053 when a deployment was commanded while a firing loop fault was present, a code that cannot be erased after a front airbag deployment.
- What you may notice
- Airbag or rear belt warning lamp on
- Rear belt display shows the left seat wrongly as fastened or unfastened
- Safety note: the buckle plug sits under the seat near pretensioner and side airbag plugs; only unplug it with the battery disconnected and the wait time observed
- Likely causes
- LikelyLoose or corroded buckle connector under the left rear seat
- PossibleFaulty switch or Hall sensor in the left rear buckle
- PossibleLead damaged by folding or sliding the second-row seat
- RareOlder GM/Saab module: deployment record with a loop fault, module replacement needed
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €60 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.