A damaged or disconnected electrical connector at the driver-side curtain airbag module, often caused by prior trim removal or body work.; A broken or chafed wire in the stage-2 squib circuit, typically where the harness passes through the headliner or pillar.; Corrosion or water intrusion at the airbag connector or in the kick-panel harness, leading to high resistance.; A defective driver-side curtain airbag assembly with an internal open or short in the stage-2 squib.; A faulty SRS control module that incorrectly interprets a good circuit as a fault.; Improperly performed repairs that left the airbag circuit unplugged or the battery disconnected during service, setting a history code.

DTC codes / B00xx · Airbags, seats, doors, lights and comfort systems / B0030

B0030Driver Side Curtain Airbag Stage 2

Q: What does code B0030 mean?

Driver Side Curtain Airbag Stage 2. B0030 indicates that the supplemental restraint system (SRS) control module has detected a fault in the second deployment stage of the driver-side curtain airbag, which is the airbag that drops down from the roofline to protect the driver's head in a side impact. The computer monitors the resistance of the stage-2 squib circuit and sets this code when the measured value falls outside the expected range, typically signaling an open circuit, a short to ground or power, or a defective airbag module.

B0030 indicates that the supplemental restraint system (SRS) control module has detected a fault in the second deployment stage of the driver-side curtain airbag, which is the airbag that drops down from the roofline to protect the driver's head in a side impact. The computer monitors the resistance of the stage-2 squib circuit and sets this code when the measured value falls outside the expected range, typically signaling an open circuit, a short to ground or power, or a defective airbag module.

SystemBody

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

The airbag warning light on the instrument cluster stays illuminated after the bulb-check sequence.
A message such as 'Service Airbag' or 'SRS Fault' may appear on the driver information display.
The driver-side curtain airbag will not deploy in a side impact or rollover event while the fault is present.
Other airbag-related systems, such as seatbelt pretensioners, may be disabled as a fail-safe measure.
Often no symptoms besides the warning light, because the fault is electrical and does not affect drivability.

Common causes, most likely first

A damaged or disconnected electrical connector at the driver-side curtain airbag module, often caused by prior trim removal or body work.
A broken or chafed wire in the stage-2 squib circuit, typically where the harness passes through the headliner or pillar.
Corrosion or water intrusion at the airbag connector or in the kick-panel harness, leading to high resistance.
A defective driver-side curtain airbag assembly with an internal open or short in the stage-2 squib.
A faulty SRS control module that incorrectly interprets a good circuit as a fault.
Improperly performed repairs that left the airbag circuit unplugged or the battery disconnected during service, setting a history code.

How to diagnose and fix it

Connect a scan tool and record all SRS codes, then clear the codes and verify whether B0030 returns immediately or only after a road test.
Inspect the driver-side curtain airbag connector under the headliner and the corresponding SRS module connector for looseness, corrosion, or bent pins.
Perform a resistance measurement on the stage-2 squib circuit with a digital multimeter, following the manufacturer's procedure, to check for an open or short.
Check the harness routing along the driver-side roof rail and A-pillar for chafing, pinches, or damage from previous repairs.
If the circuit tests good, substitute a known-good driver-side curtain airbag and clear the codes to see if the fault moves.
If the fault persists after circuit and component checks, test or replace the SRS control module according to the service information.
After any repair, clear all codes, verify the airbag light extinguishes, and confirm no codes return during a complete drive cycle.

What most technicians miss on B0030

A common oversight is replacing the curtain airbag when the real problem is a corroded connector behind the driver-side kick panel, which is exposed to water from a leaking sunroof drain.
B0030 can be set as a history code after the battery was disconnected or the airbag was unplugged during unrelated service, so always check whether the code is current or stored before condemning parts.
The stage-2 squib circuit often shares a connector with the stage-1 circuit, and a poor connection at that shared connector can set both B0030 and a stage-1 code, leading to unnecessary replacement of both airbags.
Some vehicles require the SRS module to be configured or programmed after replacement, and a used module from another vehicle will not work without proper initialization.
A faulty clock spring or seat position sensor can sometimes cause the SRS module to set multiple codes, but B0030 specifically points to the curtain airbag circuit, so do not chase unrelated components until the curtain circuit is verified.

Can I keep driving with B0030?

Because the driver-side curtain airbag is disabled while this code is stored, the vehicle will not provide full head protection in a side impact or rollover, so have it diagnosed promptly. You may drive carefully to a repair shop, but avoid aggressive driving and any situation that could lead to a side collision until the fault is fixed.

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.