What type of cable should be isolated when servicing an air bag system?

Isolating the negative battery cable when servicing an air bag system is crucial for safety. The air bag system is highly sensitive and can deploy with even minor electrical surges or shorts. By disconnecting the negative battery cable, you effectively cut off the return path for electrical current. This minimizes the risk of accidental deployment during repairs, as the air bag system is powered directly from the vehicle's battery.

While disconnecting the positive battery cable can also prevent current flow, it's the negative cable that is specifically emphasized in industry practices for working with air bag systems. This is because with the negative cable removed, any inadvertent contact with live circuits won't create a complete circuit to cause an air bag deployment.

Therefore, focusing on isolating the negative battery cable is not only a standard procedure but also a critical safety measure when working on components involving air bags, making it the recommended action in this scenario.