B1931 – Air Bag Crash Sensor #1 Feed/Return Circuit Failure

The ODBII code B1931 indicates a failure in the feed or return circuit of Air Bag Crash Sensor #1, which may affect the airbag system’s ability to deploy properly in the event of a collision.

The severity of ODBII code B1931 is typically considered moderate to high.

Common Causes For: B1930 Air Bag Safing Sensor Output Circuit Short To Ground

• Faulty airbag crash sensor
• Damaged wiring or connectors in the feed/return circuit
• Poor ground connection
• Corrosion in the connectors
• Short circuit in the wiring
• Open circuit in the wiring
• Faulty airbag control module
• Software issues in the airbag system

Common misdiagnosis for B1931 Air Bag Crash Sensor #1 Feed/Return Circuit Failure

• Faulty airbag module
• Defective crash sensor
• Wiring issues unrelated to the crash sensor
• Faulty seat belt pretensioner
• Malfunctioning airbag control unit
• Battery or power supply issues
• Incorrectly installed or damaged connectors
• Software or calibration errors in the airbag system

Common Troubleshooting Steps

When dealing with OBD-II code B1931, which indicates an issue with the Air Bag Crash Sensor #1 Feed/Return Circuit, it’s important to follow a systematic approach to troubleshoot the problem. Here are common troubleshooting steps:

• Scan Tool Verification:
• Use an OBD-II scanner to confirm the presence of the B1931 code. Check for any additional codes that may provide more context about the issue.
• Visual Inspection:
• Inspect the wiring and connectors associated with the airbag system, particularly those related to Crash Sensor #1. Look for signs of damage, corrosion, or loose connections.
• Check the airbag module and sensor mounting points for any signs of impact or physical damage.
• Check for Short Circuits:
• Use a multimeter to check for continuity in the feed and return circuits of the crash sensor. Look for any short circuits to ground or to power.
• Inspect the wiring harness for any pinched or frayed wires that could cause a short.
• Test the Crash Sensor:
• If accessible, test the crash sensor itself according to the manufacturer’s specifications. This may involve checking resistance or voltage at the sensor connector.
• If the sensor is faulty, it may need to be replaced.
• Inspect the Airbag Control Module:
• Check the airbag control module for any signs of damage or corrosion. Ensure that it is securely connected and that there are no issues with the module itself.
• If necessary, perform a reset or reprogramming of the airbag control module.
• Check for Ground Issues:
• Ensure that the ground connections for the airbag system are secure and free of corrosion. A poor ground can lead to circuit failures.
• Clear Codes and Test Drive:
• After performing repairs or adjustments, clear the trouble codes using the OBD-II scanner.
• Test drive the vehicle to see if the code returns. Monitor the airbag system for any warning lights or issues.
• Consult Technical Service Bulletins (TSBs):
• Check for any manufacturer-specific TSBs related to the B1931 code or airbag system issues. There may be known fixes or recalls that apply to your vehicle.
• Professional Diagnosis:
• If the issue persists after performing the above steps, consider seeking help from a professional technician or dealership with experience in airbag systems. They may have specialized tools and knowledge to diagnose the problem accurately. Always remember to take proper safety precautions when working with airbag systems, as they can be dangerous if mishandled. If you’re unsure about any step, it’s best to consult a professional.