Airbags

B0074 — Second Row Center Seat Belt Pretensioner Control Circuit Fault

Severity: medium Safe to drive

What B0074 means

The airbag (SRS) control module tests the squib circuit of the rear center seat belt pretensioner every time the ignition is turned on. B0074 sets when the circuit reads outside the expected range because of an open, a short, a poor connection or a failed pretensioner. While the fault is present, the pretensioner may not fire in a crash.

Symptoms

  • SRS or airbag warning light on in the instrument cluster
  • Seat belt warning light flashing or staying on
  • Chime or message about an SRS fault at ignition on
  • Occupant or airbag status indicators behaving incorrectly
  • Code returns after being cleared

Possible causes

  1. Open or short in the pretensioner wiring or connector
  2. Corroded or loose SRS connectors, often under the rear seat or on the floor
  3. Failed second row center pretensioner
  4. Harness damaged when the rear seat was moved or folded
  5. Faulty SRS control module
  6. Low supply voltage to the SRS module (uncommon)

How to diagnose

  1. Scan all SRS codes, save freeze frame data and see if the fault is current or history
  2. Check battery voltage and terminal condition
  3. Inspect the harness and connector under the rear seat for damage, corrosion or water
  4. Follow the service manual to disable the SRS, then confirm the pretensioner connector is fully seated
  5. Measure circuit resistance only per service data; never probe a squib with a standard multimeter
  6. Check the buckle switch and its connector if it is part of the circuit
  7. Substitute a known good component per factory procedure, clear the code and retest

Common fixes

  • Repair or replace damaged wiring and connectors
  • Replace the pretensioner or the center seat belt assembly
  • Replace the SRS module if confirmed faulty
  • Update SRS module software if the manufacturer offers it

Questions and answers

What does B0074 mean?

It is a fault in the control circuit of the second row center seat belt pretensioner. The SRS module sees an electrical problem in the circuit or in the pretensioner itself.

Can I drive with code B0074?

Yes, the car will drive normally. The pretensioner may not deploy in a crash, so have it diagnosed as soon as you can.

Can I just clear B0074 myself?

A scan tool can clear it, but it will return if the cause remains. Disable the SRS and follow safety procedures before touching any airbag components, as they can deploy.

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.