Incorrect thinking. A lot of things have to occur for an air bag to deploy. You have never heard a news story of that happening. There are some things you may want to be aware of related to this. The first is the electrical connections to the air bag in the steering wheel are made through a "clock spring". That is a wound-up ribbon cable in a plastic housing, right under the steering wheel. Over time, that cable can break on one end, creating an "open circuit". That just means a circuit with a break in it. At that point, the air bag can be set of by static electricity. It is theoretically possible to generate over 3,000 volts of static electricity from sliding across the seat, but then you would have to get inside the clock spring to touch one of the broken wires. I haven't heard of that happening either.
I did run into one clock spring that had been ignored for so long, the ribbon cable started creeping out under the steering wheel. Normally that is not possible as it is contained inside the housing, but that one had been cobbled by the owner.
For demonstration purposes, an air bag can be lit off with a 9-volt transistor battery, so it's easy to understand that static electricity can do it too.
The next thing is the circuit going from the Air Bag Computer to the air bag has multiple connectors. One is right under the air bag. Another is at the computer, and one is under the clock spring assembly or on a cable leading up to the clock spring. That can be at the base of the steering column. Connectors in that circuit will always be bright yellow. Disconnecting one of those would render the system inoperative but leave it with that dreaded open circuit. To make this system safe to work on, those connectors will always have a shorting bar in them on the air bag side. When its disconnected, that bar drops down to short the two wires together. That makes them immune to static electricity. Even if they're hit with 3,000 volts, they're both hit equally. The difference between them is still 0.0 volts, so the rocket fuel pellet is not ignited. Toyota used to advertise that their connector terminals and shorting bars were gold-plated for the best possible connection. In fact, all air bag connectors from all manufacturers are gold-plated.
The bigger problem with disabling a safety system is the liability issue if you're involved in a crash. Any lawyer or insurance investigator is going to find that. That will make you at least partially at fault for your injuries, even if the crash was the other guy's fault. Air Bag computers have data recorders built in. We can't get into them, but car manufacturers can, to retrieve that data. That will tell the lawyer if you were speeding, if you failed to brake, and on newer models, what you were doing with the steering wheel. That data can also prove you were not speeding, or you were braking to avoid the crash.
I've never been in a crash where an air bag deployed, but I did run a race car into a sand trap. It went from 70 mph to 0 mph in about 20 feet. That felt like hitting a cement wall and left a bruise on my chest from the seat belt. A crash from just 40 mph to 0 mph in a couple of feet hurts a lot more.
Normal operation of the Air Bag warning light is to turn on for six seconds when the ignition switch is turned on, as a bulb check. It should turn off after that. If it stays on or flashes, that indicates a defect has been detected. Any time that happens, the computer turns the system off and will not deploy the bag. There are always two fuses that run this system. If one of them blows, the system gets turned off, and the other circuit is there to run the warning light.
There will also be a diagnostic fault code in that computer. Before you do anything, have that code read and recorded. Get the exact code number, not just the description. Most inexpensive code readers only read codes in the Engine Computer. Some of the newer ones also read codes in the Air Bag, and Anti-lock Brake Computers. Otherwise, you'll need a regular scanner to read these codes. The people at many auto parts stores will read them for you for free, but remember, they're in the business of selling parts. Fault codes may reference a sensor or other part, but that never means that part is bad. It could be, but it's just as likely a wire or connector is the cause of that code. Once you know the code number, let me know and I'll look up the definition for you.
Here's links to some dandy articles you might find of interest:
https://www.2carpros.com/articles/how-airbag-safety-systems-work
https://www.2carpros.com/articles/symptoms-of-a-bad-airbag-clock-spring
https://www.2carpros.com/articles/how-to-gather-airbag-safety-system-codes
https://www.2carpros.com/articles/air-bag-removal-steering-wheel
This last one includes information on safety when working with air bags.
Thursday, March 6th, 2025 AT 11:47 AM
