An air bag does not deploy in every collision. The investigation must first determine what the vehicle sensed, which restraints were designed to activate, and whether the crash met the system’s deployment criteria. That work depends on preserving the vehicle before power, repair, salvage, or dismantling changes the evidence.
Freeze the vehicle in its post-crash condition
Document the battery state, ignition position, warning lamps, steering wheel, dashboard, seats, belts, buckles, pretensioners, sensors, wiring, and visible damage. Photograph the entire vehicle, crush paths, underbody, passenger compartment, occupant contacts, and all deployed or undeployed restraints. Record the VIN, tow location, keys, and every person who has controlled the vehicle.
Do not clear diagnostic codes, connect a charger, turn on the ignition, repair wiring, or remove restraint components before a qualified inspection plan is in place. A well-meaning shop can overwrite or alter the most useful evidence.
Reconstruct the crash the system experienced
Air-bag analysis begins with direction, severity, duration, and location of impact, not simply the amount of visible body damage. Collect scene measurements, vehicle photographs, video, police data, witness accounts, damage to the other vehicle, and evidence of secondary impacts or rollover.
Seat position, occupant size, seat-belt use, pretensioner activity, child-seat status, and occupant classification may affect restraint operation. Those facts should be documented without assuming they excuse or establish a failure.
Preserve electronic and component evidence
A controlled download may recover event data, restraint-control information, diagnostic trouble codes, and deployment commands. Identify the tool, software version, technician, power method, and every file created. Keep the original download as well as the report.
The inspection should identify sensors, control modules, inflators, clockspring, connectors, wiring, and prior replacement parts. Any teardown should follow a written protocol that allows all interested parties to document the component before it changes.
Check repair, warning, and recall history
Collect purchase, service, collision-repair, salvage, and inspection records. A prior deployment may not have been repaired correctly, and replacement parts may differ from the original system. Photographs from an earlier loss can show whether modules, sensors, or structural areas were disturbed.
NHTSA states that a failure to deploy in an injury-producing crash may be reported for possible defect investigation and provides current air-bag safety information. Its VIN recall lookup can identify open recalls. A complaint or recall is evidence to investigate, not proof that the same condition caused this event.
Separate crash injury from enhanced injury
Medical and biomechanical review should address whether a properly functioning restraint probably would have changed the occupant’s injuries. That requires matching injury locations, occupant movement, belt evidence, interior contacts, and crash forces. The claim may involve the manufacturer, component supplier, repairer, seller, or another vehicle, but their roles should be evaluated separately.
A Louisiana defective-products lawyer can coordinate vehicle preservation and engineering review. The firm’s published guides on air-bag injury proof and automotive defects explain related evidence issues.
Editorial & Legal Accuracy Notice (Louisiana)
Sources checked: September 24, 2026
Deployment criteria, product condition, prior repair, causation, and enhanced injury require vehicle-specific technical and medical analysis.