Airbags

B0072 — Passenger Seatbelt Pretensioner A Deployment Control Circuit Fault

Severity: medium Safe to drive

What B0072 means

The SRS (airbag) control module continuously tests the passenger seatbelt pretensioner circuit, checking resistance, voltage and communication with the deployment driver. B0072 is set when the readings fall outside the allowed range or communication is lost. The system then disables that pretensioner and turns on the SRS warning light.

Symptoms

  • SRS or airbag warning light on, steady or flashing
  • Intermittent restraint system warning chime
  • Passenger pretensioner may not activate in a crash
  • Other SRS codes stored in the module

Possible causes

  1. Damaged or corroded connector under the passenger seat
  2. Open or shorted wiring in the pretensioner circuit
  3. Faulty pretensioner or its control module
  4. Low system voltage or a poor ground
  5. Corrupted module software or calibration (uncommon)

How to diagnose

  1. Scan all SRS codes with a scan tool that supports airbags and note the freeze-frame data
  2. Check battery voltage and the condition of terminals and grounds
  3. Inspect harness and connectors under the passenger seat and near the body pillar, especially if the seat was moved or removed
  4. Make sure connectors are fully latched and the pins are not corroded
  5. Disconnect the battery and wait the time specified by the manufacturer before touching any SRS wiring
  6. Test circuit resistance only with the methods and tools the service manual allows; never probe a squib with a regular meter
  7. Clear the code and see whether it returns

Common fixes

  • Repair or replace damaged wiring and connectors in the pretensioner circuit
  • Update or reprogram the module with OEM software
  • Replace the pretensioner or control module with a VIN-matched unit
  • Correct any power supply or ground problem

Questions and answers

Can I drive with a B0072 code?

Yes, the car will drive normally. But occupant protection may be reduced in a crash, so get it diagnosed soon.

Can I test the pretensioner circuit myself?

You can read the code and visually check connectors. Measuring the squib circuit and replacing SRS parts is best left to a professional, as mistakes can cause accidental deployment.

Why did B0072 come back after clearing it?

The fault is still present, most often a poor connector contact, damaged wire or a failing module. Clearing the code does not fix the cause.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.