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DTC codes / B00xx · Airbags, seats, doors, lights and comfort systems / B0071

B0071First Row Center Seat Belt Pretensioner Deployment Control

B0071 indicates that the restraint control module (RCM) has detected an open circuit, short, or excessive resistance in the deployment circuit for the first row center seat belt pretensioner, which is the pyrotechnic device that tightens the belt during a crash. The module runs a continuous self-test and sets this code when the measured circuit resistance falls outside the expected range, disabling that pretensioner to prevent an unexpected deployment.

SystemBody
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

  • The airbag or supplemental restraint system (SRS) warning light is illuminated on the instrument cluster.
  • Often no symptoms besides the warning light, because the pretensioner only functions during a collision.
  • A stored or active B0071 code retrieved with a scan tool, sometimes accompanied by other SRS codes.
  • The seat belt may feel loose or fail to lock or retract normally if the pretensioner mechanism is physically damaged.
  • In some vehicles, a chime or message on the driver information center warns of a restraint system fault.

Common causes, most likely first

  1. A disconnected, loose, or corroded electrical connector at the center seat belt pretensioner or under the seat.
  2. A damaged or pinched wire harness running to the center seat belt buckle or retractor assembly.
  3. An open or shorted pretensioner squib (the small pyrotechnic initiator) inside the seat belt assembly.
  4. Water intrusion or corrosion in the connector or wiring caused by spills or a damp floor area.
  5. A faulty restraint control module (RCM) that misreads the circuit resistance, though this is less common.
  6. Aftermarket accessories or seat repairs that disturbed the pretensioner wiring or connector.

How to diagnose and fix it

  1. Retrieve all SRS codes with a scan tool capable of reading body codes and record any freeze-frame data before clearing anything.
  2. Visually inspect the center seat belt pretensioner connector and the wiring under the seat for looseness, corrosion, or damage.
  3. Disconnect the battery and wait the manufacturer-specified time, then unplug the pretensioner connector and inspect the terminals for tightness and cleanliness.
  4. Measure the resistance of the pretensioner squib with a digital multimeter and compare it to the manufacturer's specification to rule out an open or shorted initiator.
  5. Check the wiring harness between the RCM and the pretensioner for continuity and short-to-ground or short-to-power faults.
  6. If the circuit and squib test good, substitute a known-good RCM only after confirming all other SRS circuits are intact, then clear codes and verify the light goes out.
  7. After any repair, clear the codes, perform the SRS verification test, and confirm the warning light extinguishes and stays off.

What most technicians miss on B0071

  • A common oversight is replacing the seat belt pretensioner when the real fault is a corroded connector pin or a chafed wire under the seat that only shows up when the seat is moved.
  • B0071 does not always mean the pretensioner itself has failed; a low battery or a recent jump-start can set a temporary circuit fault that clears after the battery is fully charged and codes are cleared.
  • The center seat belt pretensioner circuit often shares a connector with the seat belt buckle switch, so a fault in the buckle switch wiring can mimic a pretensioner deployment circuit problem.
  • Never use a standard ohmmeter on a live airbag or pretensioner circuit; always disconnect the battery and wait the specified time to avoid accidental deployment, and use only a meter rated for the task.
  • After a collision repair, the RCM may store B0071 if the pretensioner was deployed and not replaced, so always check for a deployed or previously deployed pretensioner before diagnosing an electrical fault.

Can I keep driving with B0071?

The vehicle remains safe to drive in normal conditions because the pretensioner only matters in a crash, but the restraint system is compromised and may not protect the center occupant properly. Avoid hard braking or any situation that could trigger a collision until the fault is repaired, and have the system diagnosed promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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