B0003 – Control of the front deployment of driver stage 3

Meaning of Code B0003

This OBD-II code indicates a configuration or communication issue with the sophisticated airbag sensor command module (SAS). The SAS is responsible for monitoring collision sensors and deploying airbags in the event of an accident. Incorrect configuration or an electrical fault prevents the system from functioning properly, compromising occupant safety.

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Severity

High Level:

• Compromised Safety: Airbags may not deploy in an accident.

• Airbag warning light illuminated continuously.

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Common Symptoms

• Airbag light illuminated on the dashboard.

• Airbag system error message displayed (depending on model).

• Complete airbag system failure (in severe cases).

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Possible Causes

1. Software configuration error in the SAS module (after reset or service).

2. Faulty SAS module (internal circuit or microprocessor failure).

3. Electrical issues:

   • Open circuit or short circuit in the wiring harness.

   • Damaged, corroded, or improperly connected connectors.

4. Faulty power supply or ground to the SAS module.

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Diagnostic Procedure

Step 1: Visual Inspection

1. Disconnect the battery (wait 15 minutes to deactivate the airbag system).

2. Locate the SAS module (usually under the driver’s seat, in the center console, or near the steering wheel).

3. Inspect the wiring harness and connectors:

   • Look for cut, chafed wires, or signs of corrosion.

   • Check the condition of the pins (bent, broken, corroded).

Step 2: Electrical Check

1. Measure the supply voltage:

   • Use a multimeter to check for 12V at the SAS power terminals.

2. Test circuit continuity:

   • Check for no short circuit or open circuit between the SAS and the airbag control unit.

Step 3: Software Diagnosis

• Use a specialized diagnostic tool (e.g., manufacturer scanner) to:

  • Read specific error codes from the airbag system.

  • Reconfigure the SAS module if necessary.

  • Update the SAS software (if TSBs recommend it).

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Recommended Solutions

• Reconfigure the SAS module using a certified diagnostic tool.

• Replace the SAS module if faulty (often requires post-installation programming).

• Repair the wiring harness: Replace damaged sections and clean connectors with contact spray.

• Restore power/ground if a fault is detected.

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Precautions

• Handle with care: The airbag system contains pyrotechnic explosives.

• Wear protective equipment (goggles, gloves) during work.

• Consult the vehicle-specific repair manual to avoid accidental deployment.