B0091 DTC – Right Front Impact Sensor Circuit Malfunction

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B0091 DTC – Right Front Impact Sensor Circuit Malfunction

The Diagnostic Trouble Code (DTC) B0091 indicates that the Supplemental Restraint System (SRS) has detected a malfunction in the right front impact sensor circuit. The right front impact sensor detects frontal collision forces and sends crash information to the SRS control module, which determines whether the front airbags should deploy. Sensor design and wiring may vary between vehicle manufacturers.

Symptoms

  • Airbag warning light illuminated.
  • Service Airbag warning displayed.
  • Front airbag system may be disabled.
  • B0091 stored in the SRS module.

Possible Causes

  • Faulty right front impact sensor.
  • Open circuit in the sensor wiring.
  • Short circuit to ground or battery voltage.
  • Loose, damaged, or corroded connector.
  • Damaged wiring harness.
  • Faulty SRS (SDM) control module.

How to Diagnose B0091

  1. Scan the SRS system and record all Diagnostic Trouble Codes.
  2. Inspect the right front impact sensor and its connector.
  3. Check the wiring harness for damage, corrosion, or loose terminals.
  4. Measure circuit continuity using a digital multimeter.
  5. Replace the sensor if the wiring passes all tests.
  6. Clear the DTC and verify that it does not return.

Typical Circuit Diagram

      SRS Control Module
             │
             │
             ▼
 Right Front Impact Sensor
             │
             │
             ▼
      Crash Signal to SDM
             │
             ▼
    Front Airbag Deployment

Repair Cost

  • Wiring repair: $30–120
  • Front impact sensor replacement: $80–250
  • SRS control module replacement: $300–900

Related DTCs

  • B0090
  • B0091
  • B0092
  • B0093

FAQ

Can I continue driving with DTC B0091?

Yes, but the front airbag system may not function correctly during a collision. The fault should be repaired promptly.

Can corrosion cause B0091?

Yes. Corrosion inside the sensor connector or wiring harness is one of the most common causes of this DTC.

Does replacing the sensor always solve B0091?

No. The wiring, connectors, and SRS control module should be inspected before replacing the impact sensor.

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