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B0030 — Second Row Left Side Airbag Deployment Control

Generic OBD-II · all makesBody

The B0030 code indicates that the second‑row left side airbag system has failed to deploy properly during a crash. It is triggered when the airbag control unit detects a fault in the deployment control circuitry for that specific passenger side airbag.

Symptoms

What causes it — most likely first

1. Faulty passenger side airbag control module

The control module may have an internal fault or damaged circuitry that prevents proper deployment.

2. Damaged or disconnected wiring harness to the passenger airbag

Loose, frayed, or severed wiring can interrupt the signal needed for deployment.

3. Defective passenger side airbag sensor or sensor cable

The sensor that monitors airbag status may be malfunctioning or its cable damaged.

4. Improperly installed or damaged airbag module

If the airbag itself is bent, cracked, or not seated correctly, deployment will be inhibited.

5. PCM/ECM communication error

In rare cases a fault in the engine control unit’s communication with the airbag system can trigger B0030, but this is much less common than hardware failures.

How it's diagnosed

  1. Check the passenger side airbag control module for fault codes and continuity;
  2. Inspect the wiring harness from the control module to the airbag for signs of damage or disconnection;
  3. Verify the passenger side airbag sensor cable is intact and connected;
  4. Confirm the airbag module is correctly installed and free of physical damage;
  5. Run a system reset and re‑store any stored codes to see if the fault reappears;
  6. If the fault persists, test the PCM/ECM communication link to the airbag control unit.

Code facts & related codes

SystemBody
StandardizationSAE generic — identical on every make

Vehicles this code applies to

The definition is universal; the diagnostics are engine-specific. Open your vehicle for the codes documented for it:

2023 Lexus NX450h+2023 Lexus RC F

Frequently asked

Can a B0030 code be caused by a faulty PCM instead of the airbag system?

While the PCM can occasionally trigger airbag fault codes, B0030 is almost always due to a hardware fault in the passenger side airbag control module, wiring, or airbag itself. A PCM replacement is rarely the correct solution.

Will the vehicle be safe to drive with a B0030 code?

The vehicle will still be operable, but the passenger side airbag will not deploy in a crash, reducing occupant protection on that side. It is recommended to have the fault addressed before driving.

Does a B0030 code mean the passenger side airbag is permanently damaged?

Not necessarily. The code indicates a failure in deployment control; after repairing or replacing the faulty component, the airbag should function normally.