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      Subaru SRS (Supplemental Restraint System)/Airbag Diagnostic Trouble Codes (DTCs)

      Comprehensive Guide to Subaru Airbag/SRS Diagnostic Trouble Codes (DTCs) and Troubleshooting

      When the airbag warning light activates in your Subaru vehicle, it is a critical indicator of a potential issue within the Supplemental Restraint System (SRS). Swift action is essential to ensure both safety and the correct operation of your vehicle. This guide offers a detailed exploration of common Subaru SRS/Airbag DTC codes, Subaru’s unique SRS system features, troubleshooting strategies, and professional repair solutions. Components that MyAirbags can rebuild or service are also highlighted to help you resolve the issue efficiently and cost-effectively.

      Understanding the Subaru SRS/Airbag System

      Subaru vehicles are built with advanced safety systems, including a robust SRS/Airbag setup designed to protect occupants during collisions. The system integrates several key components:

      • SRS Airbag Control Module (ACM): This module monitors the airbag system and controls airbag deployment in the event of a collision.
      • Airbags: Subaru vehicles feature multiple airbags (frontal, side, curtain, and knee) that provide protection across various impact scenarios.
      • Seat Belt Pretensioners: These tighten the seat belts upon impact, securing the occupants more effectively.
      • Impact Sensors: These sensors detect a collision and relay crucial information to the ACM.
      • Occupant Detection System (ODS): This system determines whether a front passenger is present and adjusts airbag deployment based on weight.
      • Passenger Airbag ON/OFF Indicator: An indicator that communicates whether the passenger airbag is activated or deactivated, depending on the ODS.

      Key Features of the Subaru SRS System

      1. Subaru’s Advanced Occupant Detection System (ODS)

      The ODS in Subaru vehicles uses weight and position sensors to determine the presence and size of the front passenger. This system helps adjust the deployment of the airbags, deactivating them when a small child or no passenger is detected, enhancing safety.

      2. All-Around Airbag Protection

      Subaru vehicles include a comprehensive airbag setup, with frontal, side, curtain, and knee airbags designed to protect occupants from every angle in the event of a collision.

      3. Subaru’s Reinforced Body Structure

      Subaru integrates the SRS system with their high-strength, reinforced body structure to enhance passenger safety. This structure absorbs and disperses crash energy, reducing the impact on occupants.

      Common Subaru SRS/Airbag DTC Codes

      Here is a detailed list of common Subaru SRS/Airbag DTC codes, their explanations, possible causes, and recommended solutions. MyAirbags can rebuild or service several of these components to ensure a reliable and cost-effective repair.

      SRS Airbag Control Module (ACM) Faults

      DTC B1650 - SRS Control Module Fault

      • Description: The airbag control module has detected an internal malfunction.
      • Possible Causes: Hardware failure, software corruption, moisture damage, or power supply issues.
      • Professional Solution: MyAirbags can reset and repair the ACM, restoring it to factory specifications.

      DTC B1655 - ACM Coding Error

      • Description: Incorrect coding or configuration in the ACM.
      • Possible Causes: Faulty programming or software errors, especially after module replacement.
      • Professional Solution: Reprogram the ACM using Subaru diagnostic software. MyAirbags can assist with reprogramming and resetting the ACM.

      Airbag Deployment Circuit Faults

      DTC B1801 - Driver’s Airbag Squib Circuit Open

      • Description: An open circuit is detected in the driver’s airbag inflator circuit.
      • Possible Causes: Faulty wiring, damaged clock spring, poor electrical connections, or a defective airbag module.
      • Professional Solution:
        • Repair Wiring: Inspect and repair any damaged wiring.
        • Replace Clock Spring: If the clock spring is faulty, replace it.
        • Replace Airbag Module: Airbag modules must be replaced as they cannot be repaired.

      DTC B1805 - Passenger’s Airbag Squib Circuit Open

      • Description: Open circuit detected in the passenger’s airbag deployment circuit.
      • Possible Causes: Similar to B1801, including faulty wiring or defective airbag module.
      • Professional Solution: Repair the wiring and connectors or replace the passenger airbag module if necessary.

      Seat Belt Pretensioner Faults

      DTC B1901 - Driver’s Seat Belt Pretensioner Circuit Open

      • Description: Open or short circuit in the driver’s seat belt pretensioner.
      • Possible Causes: Damaged pretensioner, faulty wiring, or connector issues.
      • Professional Solution: MyAirbags can rebuild and repair seat belt pretensioners to ensure they function correctly.

      DTC B1905 - Passenger Seat Belt Pretensioner Circuit Open

      • Description: Similar issue as B1901 in the passenger seat belt pretensioner circuit.
      • Possible Causes: Similar to the driver’s side.
      • Professional Solution: MyAirbags offers rebuilding and repair services for passenger seat belt pretensioners.

      Occupant Detection System (ODS) Faults

      DTC B1870 - Occupant Detection Sensor Malfunction

      • Description: The ODS sensor is malfunctioning, leading to improper airbag deployment control for the front passenger.
      • Possible Causes: Faulty ODS sensor mat, wiring issues, or calibration problems.
      • Professional Solution: Replace the ODS sensor mat and recalibrate the system using Subaru diagnostic equipment.

      DTC B1875 - ODS Communication Error

      • Description: Communication error between the ODS and ACM.
      • Possible Causes: Wiring faults, damaged connectors, or defective modules.
      • Professional Solution: Inspect and repair wiring, replace defective connectors, and recalibrate the system if necessary.

      Impact Sensor Faults

      DTC B1019 - Front Impact Sensor Communication Error

      • Description: A communication fault with the front impact sensor.
      • Possible Causes: Sensor damage, poor wiring connections, or mounting issues.
      • Professional Solution: Replace the front impact sensor and ensure proper wiring and installation.

      DTC B1020 - Side Impact Sensor (Driver) Fault

      • Description: Communication failure with the driver-side impact sensor.
      • Possible Causes: Faulty sensor, wiring problems, or connector issues.
      • Professional Solution: Replace the defective sensor and check all related wiring and connections.

      Additional SRS/Airbag Troubleshooting Information

      Clock Spring (Spiral Cable) Issues

      • Symptoms: Airbag warning light stays on, malfunctioning steering wheel controls, horn not working.
      • Causes: Damaged clock spring due to wear, improper installation, or broken wiring within the assembly.
      • Professional Solutions:
        • Test for Continuity: Use professional diagnostic tools to test the clock spring for continuity.
        • Replace Clock Spring: If found faulty, replace the clock spring. Ensure proper alignment during installation to prevent further issues.

      CAN Communication Errors

      DTC U0151 - Lost Communication with SRS Control Module

      • Description: The ACM has lost communication with other vehicle modules on the Controller Area Network (CAN) bus.
      • Possible Causes: Faulty ACM, network communication issues, or damaged wiring.
      • Professional Solution:
        • Inspect and Repair Wiring: Check CAN bus wiring and repair any faults.
        • Reset Modules: Use Subaru diagnostic software to reset the system. MyAirbags can repair or reset the ACM if necessary.

      Troubleshooting and Repair Procedures

      Step 1: Retrieve Diagnostic Trouble Codes

      • Use Subaru Diagnostic Tools (e.g., Subaru Select Monitor):
        • Connect the diagnostic tool to the vehicle’s OBD-II port.
        • Retrieve all stored and pending DTCs for an accurate diagnosis.

      Step 2: Conduct a Visual Inspection

      • Wiring and Connectors: Inspect for signs of damage, wear, corrosion, or loose connections.
      • Sensors and Modules: Check for physical damage and ensure secure mounting.

      Step 3: Test and Replace Faulty Components

      • Airbag Modules: Replace defective airbag modules as they cannot be repaired.
      • Seat Belt Pretensioners: MyAirbags can rebuild and repair these components to OEM standards.
      • Clock Spring: Test for continuity and replace if necessary.
      • Impact Sensors: Replace any damaged or malfunctioning sensors.

      Step 4: Reprogramming and Calibration

      • Occupant Detection System Calibration: After replacing components, recalibrate the ODS using Subaru diagnostic tools.
      • SRS Control Module Reprogramming: Ensure the ACM is programmed correctly for the vehicle.

      Step 5: Clear DTCs and Verify Repairs

      • Clear Codes: Use the diagnostic tool to erase stored DTCs.
      • Test Drive and Recheck: Verify that the airbag light remains off and that no new codes appear.

      Safety Precautions and Professional Recommendations

      • Disconnect Battery: Before conducting SRS repairs, disconnect the negative battery terminal and wait at least 10 minutes to avoid accidental airbag deployment.
      • Handle Components with Care: Airbag modules and pyrotechnic devices must be handled carefully to prevent injury.
      • Use Professional Equipment: Always use insulated tools and professional diagnostic equipment to ensure accurate and safe repairs.
      • Consult Certified Technicians: For complex issues, consult with Subaru-certified professionals.

      Why Choose MyAirbags

      MyAirbags offers specialized services for Subaru vehicles, including:

      • SRS Airbag Control Module Reset and Repair: Clearing crash data and restoring the ACM to factory condition, saving you the cost of buying a new module.
      • Seat Belt Pretensioner Rebuilding: Repairing and resetting seat belt pretensioners to ensure they meet OEM safety standards.
      • Cost-Effective Solutions: Offering significant savings compared to replacing components with new OEM parts.
      • Quality Assurance: All repairs are completed to OEM standards, with thorough testing to ensure proper functionality.

       

      Effectively addressing SRS issues in Subaru vehicles requires an in-depth understanding of the system's components, diagnostic codes, and troubleshooting methods. By following this guide and utilizing MyAirbags' professional repair services, you can restore your vehicle's safety features while saving time and money.

      Disclaimer

      This guide is intended for informational purposes and may not cover all possible scenarios or Subaru models. Always consult your vehicle’s service manual and refer to a qualified technician for accurate diagnostics and repairs. MyAirbags provides professional repair and reset services for SRS components in compliance with safety standards.

      By understanding these DTCs and following the prescribed troubleshooting steps, you can effectively resolve SRS issues in your Subaru. Utilizing expert services like MyAirbags ensures that your safety systems are restored to their original condition, keeping you and your passengers safe on the road.