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

Our certified mechanics come to you · Get a fair and transparent estimate upfront

EXCELLENT RATING ON

Cost of diagnosing the B1931 code

B1931 is a diagnostic trouble code (DTC) for "Air Bag Crash Sensor 1 Feed/Return Circuit Failure". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $154.99 . Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $50.0 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate* Credit towards follow-up repair Earliest Availability
Ford $154.99 $50.0
Toyota $154.99 $50.0
BMW $164.99 $50.0

*Estimates may vary by market

SCHEDULE B1931 DIAGNOSTIC Get a fair and transparent estimate upfront

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.

OBD-II
trouble codes
B1931

No more waiting rooms! Our mechanics will come to you to diagnose and fix the B1931 code.

SCHEDULE B1931 DIAGNOSTIC
Get a $50 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(8600)

Rating Summary
8017
273
65
46
199
8017
273
65
46
199
 at YourMechanic

Brandon

9 years of experience
133 reviews
Brandon
9 years of experience
Ford Escort L4-2.0L - Check Engine Light is on - Nashville, Tennessee
Brandon showed up ahead of schedule, was very personable and diagnosed my problems. He also scheduled my next appointments which will be with him.
 at YourMechanic

William

23 years of experience
33 reviews
William
23 years of experience
Lexus IS250 V6-2.5L - Check Engine Light is on - Mableton, Georgia
Arrived early which was great. William was courteous, and attentive to the issue. Even though it took several attempts I'm so happy he was determined to fix it and he did!
 at YourMechanic

Dan

40 years of experience
1080 reviews
Dan
40 years of experience
Plymouth Grand Voyager - Check Engine Light is on - Lawrenceville, Georgia
Mr. Dan Barber was quite patient, courteous and quite knowledgeable. From my observation, Mr. Barber appears to be quite professional.
 at YourMechanic

Christopher

9 years of experience
120 reviews
Christopher
9 years of experience
Ford Fiesta L4-1.6L - Check Engine Light is on - Smyrna, Georgia
Chris communicated with us each step of the way up until his arrival. He listened well, was knowledgeable, and was prepared. He took the time to diagnose the problem, explained the what, why and how and provided a solution. I would definitely recommend him and will use him again.


More related articles

P2193 OBD-II Trouble Code: System Too Lean at Higher Load Bank 2
P2193 P2193 code definition System Too Lean at Higher Load Bank 2 What the P2193 code means P2193 is an OBD-II generic code for the Engine Control Module (ECM) detecting the fuel control has reached its rich limits when the...
P0366 OBD-II Trouble Code: Camshaft Position Sensor "B" Circuit Range/Performance (Bank 1)
P0366 P0366 code definition The P0366 code is defined as an incorrect voltage reading from the camshaft position sensor circuit, specifically for the engine bank 1 camshaft sensor B. What the P0366 code means In order to control fuel injection...
P0469 OBD-II Trouble Code: Purge Flow Sensor Circuit Intermittent
P0469 means the evaporative (fuel) system has a problem with the purge flow sensor, often due to a damaged charcoal canister or faulty flow sensor.

Related questions

seems to be stuck in 2nd or 1st cant tell
Here are a few things to check next: With a fully charged battery, test the voltage on the ERLS fuse, Key On Engine Off (KOEO) and the transmission connector connected. If the voltage is low at the fuse, replace the...
I have a 1986 Chrysler Laser turbo with 13700 miles that failed emissions. Do oxygen sensors go bad from sitting around too long?
Wow, I almost bought one of these new back in 1986. It is possible that due to age, any number of sensors can be bad, even without a Check Engine Light being set. The best way to determine that is...
Smog check failed due to Oxygen sensor
Hello, thank you for writing in. The first person to tell you this was correct to a certain extent. If the system is not warmed up, the readings cannot be taken accurately. However, if the engine is warmed up and...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com