Tech Tip: Avoid Unintended Air Bag Deployment

Vehicles Involved: 2009–2020 GM Passenger Cars and Trucks

To avoid inadvertent deployment of a vehicle air bag while servicing, it is recommended technicians take a few precautions when working on or near the vehicle’s Supplemental Inflatable Restraint (SIR) system.

According to Service Information (SI), the SIR system must be disabled whenever performing service on or near any of its components or wiring. The SIR component location affects how a vehicle should be serviced. There are parts of the system installed at various locations around a vehicle. To find the location of the SIR components, refer to the SIR Identification Views in SI.

There are several reasons for disabling the SIR system, such as repairs to the SIR system or servicing a component near or attached to an SIR component. In addition to disabling the SIR system, the ignition/vehicle should be in the OFF position for any service work that requires impact to the body or frame (for example, when adjusting the side door striker using a hammer or mallet).

WARNING: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Failure to observe the correct procedure could cause deployment of the SIR airbags/tensioners, which could result in serious injury or unnecessary SIR system repairs. The inflatable restraint Sensing and Diagnostic Module (SDM) fasteners should not be removed until the battery is disconnected and the SDM electrical connector is removed.

The fasteners should be reinstalled and torqued to proper specifications before reattaching the SDM electrical connector. The electrical connector must be reattached before reconnecting the negative battery cable to the battery. The SDM is equipped with a roll-over sensor. Turning the SDM over while under power may result in air bag deployment. The SDM maintains a reserved energy supply. The reserved energy supply provides deployment power for the air bags if the Inflatable Restraint Sensing and Diagnostic Module loses battery power during a collision. Deployment power is available for as long as 2 minutes after disconnecting the vehicle power. Wait 2 minutes before working on the vehicle after disabling the SIR system to prevent deployment of the air bags from the reserved energy supply.


  1. Turn the steering wheel so that the vehicle wheels are pointing straight ahead.
  2. Vehicle OFF
  3. Disconnect the negative battery cable from the battery. Refer to the Battery Negative Cable Disconnection and Connection in SI.
  4. Wait 2 minutes before working on the vehicle.
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