Skip the auto shop - Our mechanics make house calls

B1931 OBD-II Trouble Code: Air Bag Crash Sensor 1 Feed/Return Circuit Failure

diagnostic check engine light

B1931 code definition

The B1931 trouble code indicates that the airbag deployment system’s Sensor 1 has been reported as malfunctioning by the airbag electronic controller unit (ECU).

What the B1931 code means

The airbag's crash sensor serves to gauge the force of impact and determine whether or not the situation warrants deploying the airbag. A successful airbag deployment must be triggered by both the crash sensor and safing sensor. If a circuit failure has been detected in the airbag's crash sensor, it will disable the vehicle's airbag function.

What causes the B1931 code?

In many cases, a B1931 trouble code is caused by a malfunctioning crash sensor. If this is the case, it will need to be replaced. Problematic wiring is another common cause for this issue. In rare cases, the code may be mistakenly reported by a malfunctioning ECU.

What are the symptoms of the B1931 code?

If the crash sensor circuit is malfunctioning, the airbag system won't be activated in the event of a crash. In addition to the practical symptoms, a stored trouble code and illuminated trouble lamp on the dashboard will be present in a purely diagnostic facility.

How does a mechanic diagnose the B1931 code?

A mechanic can first identify the B1931 by reading the computer with an OBD-II code scanner. All wiring between the ECU and sensors should be checked out for signs of corrosion, damage, disconnection or faultiness. The crash sensor itself should be examined and tested in order to see if it is faulty.

Common mistakes when diagnosing the B1931 code

Body-related trouble codes tend to be specific to certain manufacturers and vehicle makes. A B1931 code may describe different issues depending on the vehicle in question. As such, one code description may be addressed instead of another.

How serious is the B1931 code?

In the event of a B1931 trouble code, the airbag should be considered non-operational. Although the vehicle's drivability won't be affected (unless the issue is more far-reaching) the lack of a working airbag system may pose significant concerns with regards to safety.

What repairs can fix the B1931 code?

Any wiring that has been identified as being damaged or faulty should be repaired or replaced accordingly. If any components related to airbag deployment have been cited as malfunctioning, they should be repaired or replaced. If the ECU has been cited as faulty, it should be repaired or reprogrammed. Following repairs to the B1931 code, the vehicle should be retested. If the code does not return, it will verify that the issue has been solved.

Additional comments for consideration regarding the B1931 code

Airbag components are typically found on the passenger's side of the vehicle, behind the kick panel. Check your vehicle user manual for specific instructions on how to access the airbag deployment system.

Need help with a B1931 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How Long Does a Throttle Return Spring Last?
Not all vehicles on the road feature an electronic throttle control (ETC), which is also called drive-by-wire. For vehicles that don't offer this system, they have a throttle cable instead that...
P0121 OBD-II Trouble Code: TPS "A" Circuit Range Performance Problem
P0121 code definition Throttle Pedal Position Sensor/Switch (TPS) A Circuit Range Performance Problem What the P0121 code means P0121 is a generic OBD-II code which indicates that the Engine Control...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...


Related questions

Q: A scanner found the code P02B4, what does it mean?

That is an interesting code since your engine only has 4 cylinders. It is possible that the vehicle has the wrong information stored in the computer and is throwing a code for a V-8 engine. I recommend having your computer...

Q: I would like to collect brake pedal position information from my OBD2 port. Can this be done?

The brake pedal position does not have a specific wire to the OBD2 connector that can be monitored. You could however monitor the data stream and get the brake on or off PID in the data monitoring. The PID will...

Q: Stalling,bad fuel mileage,won't start without Acceleration, rough idling.

This may be related to a couple of different things. I would recommend checking the idle air control valve/module which works similar to the MAF sensor in that it regulates air intake as it is mixed with fuel prior to...