A Posting From Forum Moderator Ron Moore

Received a question from a concerned Fire Captain regarding airbag drain times. I'm sharing his question and my reply more as a reminder than anything new. It's a good point and something I just want to make sure that all of us have presented to our 'troops' so much so that it is second nature to them to do during daily vehicle rescue operations.

Question:
Dear Ron,
Can you give me an amount of time(approximately) once the electrical system has been shutdowm. As to how much time the Air-bag could still deploy. My cousin works for a GM Dealer, and they are saying 1 minute after the battery is disconnected the air-bags shouldn't deploy.Is this only for GM products? I am just looking for a general rule to tell my crew, about all vehicles. Thanks ahead of time.


My Reply:
Air bag capacitor drain times are getting shorter. The normal drain time for a new model vehicle is now between 2 minutes and 5 minutes; some even have less than one minute drain times(BMW for example). It is encouraging that GM is saying one minute. That's good news.

There are two critical points that your crews must be aware of. First, nothing starts getting better until you accomplish total electrical system shutdown. Access the battery (or batteries) and disconnect or "double-cut" ALL cables. Negative first but then the positive cables as well.

Secondly, even with power shutdown and the capacitor drained, a loaded airbag must still be respected for its potential to deploy at any time. Make sure your crews are aware that there is NOTHING we can do that will ever render an undeployed airbag completely, 100% guaranteed NOT to go off. Static electric charges, sensitivity to vibration, moisture, heat, etc are all reasons that millions of installed airbags have been recalled in past years models.

Accomplish airbag scanning everytime. Maximum number of actual airbags in any one vehicle is now 12 (2002 BMW 745i) although there are 16 possible locations to check for airbags.

Complete total electrical system shutdown as deemed appropriate for the situation.

Remain clear of the 10"-18"-5" inflation zones for all loaded airbags!