WOMS
B code body High severity

B1901 Air Bag Crash Sensor #1 Feed/Return Circuit Short To Ground

The OBD2 code B1901 indicates a short circuit in the feed or return circuit of Air Bag Crash Sensor #1, which can prevent the airbag system from functioning properly

Definition

The OBD2 code B1901 indicates a short circuit in the feed or return circuit of Air Bag Crash Sensor #1, which can prevent the airbag system from functioning properly

Common causes

  • Damaged wiring or connectors
  • Shorted wires in the airbag system
  • Faulty airbag crash sensor
  • Corroded connectors
  • Poor ground connections
  • Water intrusion or moisture in the circuit
  • Improper installation or modifications to the airbag system

Common misdiagnoses

  • Faulty airbag control module
  • Defective crash sensor
  • Wiring harness issues
  • Poor ground connections
  • Faulty seat belt tensioner
  • Malfunctioning airbag indicator light
  • Incorrectly installed or damaged airbag system components

Troubleshooting steps

  1. 1. Scan Tool Verification

  2. 2. Use an OBD-II scanner to confirm the presence of the B1901 code. Check for any additional codes that may provide more context about the issue

  3. 3. Visual Inspection

  4. 4. Inspect the wiring and connectors associated with the airbag system, particularly those related to the crash sensor. Look for signs of damage, corrosion, or loose connections

  5. 5. Check the airbag module and sensor mounting points for any signs of impact or physical damage

  6. 6. Check for Shorts

  7. 7. Use a multimeter to check for continuity in the feed and return circuits of the crash sensor. Look for any shorts to ground

  8. 8. Disconnect the crash sensor and measure the resistance of the circuit. If the resistance is too low (indicating a short), trace the wiring back to find the source of the short

  9. 9. Inspect the Crash Sensor

  10. 10. If the wiring appears intact, inspect the crash sensor itself. Check for any physical damage or signs of malfunction

  11. 11. If possible, test the crash sensor according to the manufacturer's specifications

  12. 12. Check Ground Connections

  13. 13. Ensure that all ground connections related to the airbag system are secure and free of corrosion. A poor ground can cause erratic behavior in the system

  14. 14. Clear Codes and Test Drive

  15. 15. After performing any repairs or adjustments, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code reappears

  16. 16. Refer to the vehicle's service manual for specific wiring diagrams and troubleshooting procedures related to the airbag system. This can provide valuable information for diagnosing the issue

  17. 17. Professional Diagnosis

  18. 18. If the problem persists after following the above steps, consider seeking help from a professional technician or an automotive electrician who specializes in airbag systems

  19. 19. Safety Precautions

  20. 20. Always take necessary safety precautions when working with airbag systems, as they can be dangerous. Disconnect the battery and wait for a period of time before working on the system to ensure that the airbag system is deactivated. By following these steps, you should be able to identify and resolve the issue related to the B1901 code