Damaged or pinched wiring harness in the passenger-side curtain airbag circuit, often at the roof rail or pillar; Corroded or loose connector at the passenger-side curtain airbag squib or at the restraint control module; Failed passenger-side curtain airbag module with an open stage 2 squib; Water intrusion or corrosion in the connector or harness from a leaking roof or window seal; Restraint control module internal fault on the stage 2 driver circuit; Improperly repaired wiring from a previous collision or airbag deployment

DTC codes / B00xx · Airbags, seats, doors, lights and comfort systems / B0031

B0031Passenger Side Curtain Airbag Stage 2

Q: What does code B0031 mean?

Passenger Side Curtain Airbag Stage 2. B0031 indicates that the restraint control module has detected an open circuit, short to ground, or short to voltage in the passenger-side curtain airbag stage 2 deployment circuit. The module stores this code when the measured resistance or voltage on that squib circuit falls outside the expected range during its self-test.

B0031 indicates that the restraint control module has detected an open circuit, short to ground, or short to voltage in the passenger-side curtain airbag stage 2 deployment circuit. The module stores this code when the measured resistance or voltage on that squib circuit falls outside the expected range during its self-test.

SystemBody

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

Airbag warning light illuminated steadily on the instrument cluster
Passenger-side curtain airbag may be disabled and will not deploy in a crash
Often no symptoms besides the warning light, with no drivability change
A chime or message on the driver information center stating a restraint system fault
In some vehicles, the passenger airbag status indicator may show the system as off or faulted

Common causes, most likely first

Damaged or pinched wiring harness in the passenger-side curtain airbag circuit, often at the roof rail or pillar
Corroded or loose connector at the passenger-side curtain airbag squib or at the restraint control module
Failed passenger-side curtain airbag module with an open stage 2 squib
Water intrusion or corrosion in the connector or harness from a leaking roof or window seal
Restraint control module internal fault on the stage 2 driver circuit
Improperly repaired wiring from a previous collision or airbag deployment

How to diagnose and fix it

Inspect the passenger-side curtain airbag connector and harness for damage, corrosion, or loose pins
Check for water intrusion around the roof rail, pillar, and floor harness that could corrode connectors
Measure resistance across the stage 2 squib circuit at the airbag connector and compare to specification
Perform a wiggle test on the harness while monitoring the code to locate an intermittent open or short
Repair or replace the damaged section of harness or connector using proper airbag-safe splicing methods
If the circuit tests good, substitute a known-good passenger-side curtain airbag to isolate a failed module
Clear the code and verify the repair with a scan tool and a full restraint system self-test

Before you replace the curtain airbag

A common cause of B0031 is a pinched or chafed harness at the roof rail where the curtain airbag wiring passes through a body seam, which is often missed during a visual inspection.
Water leaks from a clogged sunroof drain or failed roof seam can corrode the passenger-side curtain airbag connector and set this code without any collision damage.
The code does not always mean the airbag itself has failed; the restraint control module or a connector terminal can be the source, so circuit testing must come before parts replacement.
After any airbag circuit repair, the restraint control module may require a learn or configuration procedure with a scan tool before the warning light will clear.
A previously deployed or repaired curtain airbag with an aftermarket squib simulator can set B0031 if the simulator resistance drifts out of the module's expected range.

Can I keep driving with B0031?

The vehicle is safe to drive mechanically, but the passenger-side curtain airbag is disabled and will not deploy in a crash, so avoid carrying passengers in the rear passenger side until the fault is repaired. Do not attempt to measure or probe the airbag squib circuit with a standard ohmmeter unless you follow the manufacturer's airbag disable procedure.

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.