Body, generic

B0140 Passenger Seatbelt Tension Sensor Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Neither the J2012 code lists available here nor any carmaker's public material contains B0140; its wording repeats B0061, the J2012 code for the front passenger belt tension sensor, and resembles B0182. The part itself is well described. In Delphi's design (US6554318B2) the webbing runs through a slider that moves against springs, while a Hall element between two magnets reads the travel. A second Delphi patent (US6605877B1) sends the tension value over a two-wire line to the module that classifies the occupant, which uses it to tell a tightly strapped child seat from an adult. FMVSS 208 allows automatic passenger airbag suppression for small occupants. A fault in this circuit usually lights the airbag lamp.

Likely causes

Loose or corroded plug at the passenger belt tension sensor
Sensor signal out of range, for example from a jammed slider
Sensor lead trapped under the seat or at the sill panel

Symptoms

  • Airbag warning lamp on
  • Passenger airbag status indicator may show an unexpected state
  • Safety note: the sensor sits near pretensioner and side airbag plugs; unplug only with the battery disconnected and the wait time observed

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–600
Time0.5–2 h

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

Parts involved

seat belt tension sensoroccupant detection modulesrs seat wiringsrs control module

Related codes

B0061B0182B0060

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