DTC Codes
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      Mercedes-Benz SRS (Supplemental Restraint System)/Airbag Diagnostic Trouble Codes (DTCs)

      Mercedes-Benz Airbag/SRS Diagnostic Trouble Codes (DTCs): A Comprehensive Guide

      When working on Mercedes-Benz vehicles with an illuminated airbag warning light, understanding the specific Diagnostic Trouble Codes (DTCs) is essential for effective troubleshooting and repair. This guide covers common Mercedes-Benz SRS/Airbag DTC codes related to faulty or bad connections with the airbag control module, airbags, seat belts, impact sensors, collapsible steering column, and pyrotechnic fuses. Components that MyAirbags can rebuild or service are noted accordingly.

      Understanding the Mercedes-Benz SRS/Airbag System

      Mercedes-Benz vehicles are equipped with advanced Supplemental Restraint Systems (SRS) that include multiple sensors, modules, and actuators working together to enhance passenger safety. Faults in any of these components can trigger DTCs and illuminate the airbag warning light.

      Common Airbag Control Module Faults

      Code: B1000

      • Description: Airbag Control Unit (N2/10) Malfunction
      • Possible Causes: Internal failure, software corruption, moisture damage.
      • Solution: MyAirbags can reset and repair the airbag control module, restoring it to proper working condition.

      Code: B100A

      • Description: Airbag Control Unit Internal Fault
      • Possible Causes: Hardware defects, memory errors, voltage issues.
      • Solution: MyAirbags can reset and repair the airbag control module, addressing internal faults.

      Airbag Deployment Circuit Faults

      Code: B1004

      • Description: Driver Airbag Squib Circuit Resistance Too High
      • Possible Causes: Faulty clock spring (steering wheel spiral cable), damaged wiring, poor connections.
      • Note: Airbag modules must be replaced; they cannot be repaired.

      Code: B1005

      • Description: Passenger Airbag Squib Circuit Resistance Too High
      • Possible Causes: Defective passenger airbag module, wiring issues, connector problems.
      • Note: Airbag modules need to be replaced; they are not serviceable.

      Seat Belt Pretensioner Faults

      Code: B1015

      • Description: Driver Seat Belt Tensioner Circuit Resistance Too High
      • Possible Causes: Damaged pretensioner, faulty wiring, connector issues.
      • Solution: MyAirbags can rebuild and repair seat belt pretensioners, restoring them to functional condition.

      Code: B1016

      • Description: Passenger Seat Belt Tensioner Circuit Resistance Too High
      • Possible Causes: Similar issues as the driver's side pretensioner.
      • Solution: MyAirbags can rebuild and repair passenger seat belt pretensioners, ensuring proper operation.

      Impact Sensor Issues

      Code: B1035

      • Description: Left Front Impact Sensor Fault
      • Possible Causes: Sensor damage, wiring problems, mounting issues.
      • Recommendation: Impact sensors typically need to be replaced; repair is not recommended.

      Code: B1036

      • Description: Right Front Impact Sensor Fault
      • Possible Causes: Similar to the left front impact sensor faults.
      • Recommendation: Replace the faulty sensor to ensure proper SRS functionality.

      Collapsible Steering Column Faults

      Code: B1075

      • Description: Steering Column Module Fault
      • Possible Causes: Faulty steering column control module, wiring issues, internal faults.
      • Recommendation: May require replacement or professional repair; consult a Mercedes-Benz specialist.

      Pyrotechnic Battery Disconnect (Pyro Fuse) Faults

      Code: B1100

      • Description: Battery Disconnect Pyrofuse Activated
      • Possible Causes: Activation due to collision, faulty wiring, connector problems.
      • Solution: MyAirbags can repair or replace the pyrofuse, restoring proper circuit function.

      Additional Common Faults

      Code: B1121

      • Description: Seat Occupancy Recognition Sensor Fault (Passenger Seat)
      • Possible Causes: Damaged sensor mat, faulty wiring, connector issues.
      • Recommendation: May require sensor replacement or professional repair; consult with a specialist.

      Code: U0151

      • Description: Lost Communication with Airbag Control Module
      • Possible Causes: Faulty control module, CAN bus wiring issues, network problems.
      • Solution: MyAirbags can repair or reset the airbag control module, helping to restore proper communication.

      Troubleshooting Tips

      • Use Professional Diagnostic Tools: Utilize Mercedes-Benz Star Diagnosis System (SDS) or XENTRY Diagnostic to accurately read and interpret fault codes.

      • Perform a Thorough Visual Inspection: Check all related wiring, connectors, and components for signs of damage, corrosion, or disconnection.

      • Safety Precautions: Always disconnect the battery and wait at least 10 minutes before working on the SRS to prevent accidental airbag deployment.

      • Replace Non-Serviceable Components: Use genuine Mercedes-Benz parts to maintain system integrity and safety compliance.

      Recommendations for Salvage Rebuilders

      1. Accurate Diagnostics: Employ professional-grade diagnostic equipment to identify and understand all stored DTCs.

      2. Professional Repair Services: For repairable components like the airbag control module and seat belt pretensioners, consider utilizing MyAirbags to ensure they meet OEM standards.

      3. Regulatory Compliance: Ensure all repairs comply with local and federal safety regulations to guarantee the vehicle's roadworthiness.

      4. Documentation: Maintain detailed records of diagnostics, repairs, and parts used for transparency and future reference.

      5. Continuous Education: Stay updated on Mercedes-Benz technical service bulletins and recall notices related to the SRS/Airbag system.

      Disclaimer

      The codes listed above are generalized and may vary depending on the specific model and year of the Mercedes-Benz vehicle. For precise diagnostics, always refer to the manufacturer's service information or use a professional-grade diagnostic scanner. MyAirbags can help repair and reset specific SRS components, but it's crucial to ensure all repairs are performed by qualified professionals to maintain vehicle safety.

      By understanding these common DTCs and knowing which components can be repaired or need replacement, you can efficiently troubleshoot and resolve SRS issues in Mercedes-Benz vehicles. Utilizing professional services like MyAirbags not only saves time but also ensures that safety systems are restored to their original standards, keeping you and your passengers safe on the road.