B0140 code meaning
Passenger Seatbelt Tension Sensor Circuit
What B0140 means
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.
B0140 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0140
- 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
Common causes of B0140
- Most likelyLoose or corroded plug at the passenger belt tension sensor
- PossibleSensor signal out of range, for example from a jammed slider
- PossibleSensor lead trapped under the seat or at the sill panel
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Seat belt tension sensorOccupant detection moduleSRS seat wiringSRS control module
What each part of B0140 means
| B | Body system: airbags, seat belts, power seats, lights and climate control. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 40 | The exact fault in that area. |
What to do next
- Note B0140 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about B0140
What does B0140 mean?
B0140 means "Passenger Seatbelt Tension Sensor Circuit". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with B0140?
B0140 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0140 fail an emissions test?
B0140 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is B0140 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will B0140 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.