Airbag Safety for Technicians
Airbag Safety for Technicians
WARNING: An airbag inflator deploys with enough force to cause serious injury or death. Never place yourself in the deployment path of any airbag module. Never carry a module with the bag side facing your body. These are not guidelines — they are rules that protect your life.
Disabling the System Before Service
Any time you work near an airbag component — removing the steering wheel, dashboard, seats, or door panels — you must disable the SRS system first. Step 1: Disconnect the negative battery cable. Step 2: Wait the manufacturer-specified time for the backup capacitor in the ACM to discharge. This is usually 1 to 3 minutes depending on the manufacturer. Some vehicles require up to 10 minutes. Look it up for the specific vehicle. That capacitor stores enough energy to deploy an airbag even with the battery disconnected. Do not skip the wait.
Never Use a Test Light
Airbag circuits use very low current to fire the inflator. A test light can draw enough current to deploy the airbag while you are holding it. Never probe an airbag circuit with a test light. Use only a high-impedance digital multimeter set to the appropriate range. Even then, follow manufacturer test procedures exactly. Many systems require specific breakout tools to safely measure airbag circuits.
Handling and Storage
When you remove an airbag module, always place it with the deployment side facing up — away from surfaces. Never stack anything on top of a module. Never leave a module where it could fall. Store modules in a secure area away from heat sources and chemicals. When carrying a module, hold it with the deployment side facing away from your body at arm's length. These precautions prevent injury if an accidental deployment occurs during handling.
Connector Safety
Airbag connectors use a shorting bar. When the connector is disconnected, the shorting bar shorts the two circuit wires together. This prevents static electricity or stray voltage from accidentally deploying the module. Never bypass, modify, or remove the shorting bar. When reconnecting, listen and feel for the locking tab to click. A loose airbag connector will set a code and turn on the warning light — and more importantly, the airbag will not deploy in a crash.
After a Deployment
After a crash event where airbags deployed, the ACM, all fired modules, all fired seatbelt pretensioners, and the clockspring typically must be replaced. The ACM stores crash event data and cannot be reused. Follow the manufacturer repair procedures exactly — partial repairs leave the occupant unprotected in a future crash.