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B0074 — Second Row Center Seat Belt Pretensioner Deployment Control

Generic OBD-II · all makesBody

Code B0074 indicates a fault in the deployment control circuit for the second-row center seat belt pretensioner, which is part of the supplemental restraint system. The pretensioner is designed to tighten the belt during a collision, and this code means the restraint control module has detected an electrical problem in that specific circuit.

Symptoms

What causes it — most likely first

1. Deployed or faulty seat belt pretensioner

The pretensioner may have been activated in a previous crash or may have an internal electrical failure. Once deployed, the pretensioner must be replaced and cannot be reset.

2. Damaged or corroded wiring harness

Wiring between the restraint control module and the second-row center pretensioner can chafe, break, or corrode, especially in areas exposed to moisture or under-seat movement.

3. Poor or disconnected electrical connector

The connector at the pretensioner or at an intermediate junction may be loose, partially unlatched, or have bent or corroded pins, causing high resistance or an open circuit.

4. Faulty restraint control module (RCM/SDM)

The module that monitors the pretensioner circuit could have an internal fault, but this is uncommon and should only be considered after all wiring and the pretensioner itself have been verified.

How it's diagnosed

  1. Scan the SRS system with a capable diagnostic tool and record all stored codes, then clear and recheck to see if B0074 returns.
  2. Visually inspect the second-row center seat belt pretensioner connector and wiring for damage, corrosion, or disconnection.
  3. Perform a continuity and resistance test on the pretensioner circuit from the restraint control module connector to the pretensioner connector, comparing to factory specifications.
  4. Check the pretensioner squib resistance at the component connector using the manufacturer's specified test procedure to determine if the device is internally open or shorted.
  5. If wiring and connector checks pass and the pretensioner resistance is within spec, verify power and ground supplies to the restraint control module before considering module replacement.
  6. Replace the pretensioner only if test results confirm it is out of specification or if crash data shows it has deployed.

Code facts & related codes

SystemBody
StandardizationSAE generic — identical on every make

Frequently asked

Can I drive with code B0074?

The vehicle will drive normally, but the second-row center occupant may not have proper seat belt restraint in a crash. The SRS warning light will also remain on, which may cause inspection failure and could affect other restraint system functions.

Do I need to replace the PCM or engine computer for this code?

No. B0074 is a body/restraint system code handled by the restraint control module (RCM or SDM), not the powertrain control module. Even the restraint control module is rarely the cause — the pretensioner or its wiring is far more likely.

Can a deployed seat belt pretensioner be reset instead of replaced?

No. Once a pretensioner has fired, it is a one-time-use device and must be replaced. There is no reset procedure for a deployed pretensioner.

Is it safe to test the pretensioner circuit with a standard multimeter?

Yes, if done correctly at the harness side with the pretensioner disconnected. Never apply external voltage to a pretensioner or squib circuit, as this could cause accidental deployment. Always follow the manufacturer's diagnostic procedure.