Will an airbag still protect you, if your car is running but not moving?

Dear Car Talk | Mar 01, 2008
Dear Tom and Ray:
Will an air bag deploy if the vehicle is running but not moving? For instance, you are waiting at a red light minding your own business, and a vehicle plows into your grill. Will the air bag deploy? What if the car is turned off? Let's say you're sitting at the side of the road, out of gas, and you get hit. Will the air bag work even if the ignition is off? Thanks for knowing the answer. -- Patrick
TOM: The answer to your first question is yes, Patrick. The air bag is designed to work even when you're not driving.
RAY: If you're at a traffic light with the engine running, the air bag is absolutely powered and ready to deploy if necessary. It's ready anytime the engine is on or your ignition key is on (even if the engine is not running).
TOM: In a situation where the engine is turned off -- even if the key is removed -- the air bag will still have enough stored battery power to deploy for at least a few minutes. That covers you if you park the car and get hit while you're collecting your Sleepy LaBeef CDs and getting ready to go into your girlfriend's house.
RAY: In fact, when we do work on a steering wheel or steering column at the shop, we're always advised to disconnect the battery and let the car sit for at least half an hour to be sure that the stored power is completely depleted before we start monkeying around in the vicinity of the air bag.
TOM: The number of minutes of reserve power varies from car to car, so there's no way for us to tell you exactly how many minutes YOUR car's air bag will remain ready after you turn it off. But it's probably closer to five or 10 minutes than to 60 or 90 minutes.
RAY: But just to be safe, even after we leave the battery disconnected for half an hour, we still send my brother in first. Why should those of us who still have passable faces take that kind of risk?
Will an air bag deploy if the vehicle is running but not moving? For instance, you are waiting at a red light minding your own business, and a vehicle plows into your grill. Will the air bag deploy? What if the car is turned off? Let's say you're sitting at the side of the road, out of gas, and you get hit. Will the air bag work even if the ignition is off? Thanks for knowing the answer. -- Patrick
TOM: The answer to your first question is yes, Patrick. The air bag is designed to work even when you're not driving.
RAY: If you're at a traffic light with the engine running, the air bag is absolutely powered and ready to deploy if necessary. It's ready anytime the engine is on or your ignition key is on (even if the engine is not running).
TOM: In a situation where the engine is turned off -- even if the key is removed -- the air bag will still have enough stored battery power to deploy for at least a few minutes. That covers you if you park the car and get hit while you're collecting your Sleepy LaBeef CDs and getting ready to go into your girlfriend's house.
RAY: In fact, when we do work on a steering wheel or steering column at the shop, we're always advised to disconnect the battery and let the car sit for at least half an hour to be sure that the stored power is completely depleted before we start monkeying around in the vicinity of the air bag.
TOM: The number of minutes of reserve power varies from car to car, so there's no way for us to tell you exactly how many minutes YOUR car's air bag will remain ready after you turn it off. But it's probably closer to five or 10 minutes than to 60 or 90 minutes.
RAY: But just to be safe, even after we leave the battery disconnected for half an hour, we still send my brother in first. Why should those of us who still have passable faces take that kind of risk?
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