The supplemental inflatable restraint, or SIR, system -- commonly referred to as the airbag -- must be disarmed prior to working on the steering column, ignition switch or any of the wiring on or around the airbag system. If it is not disconnected, the airbag could be accidentally deployed, which could cause personal injury. It also results in unnecessary airbag repairs, which usually have to be done at the dealership.
Disconnect the negative battery cable, using the appropriate wrench.
Wrap the entire terminal with electrical tape, so that if it should fall and hit metal, it won't ground the battery and rearm the air bag.
Wait for two minutes before you continue with any work, so that any residual charge dissipates.
