primary air bag sensor

[pseudoboyfriend]

I've had a code 9 for a while, and have been trying to fix it. As near as I can tell, the primary sensor is bad (not the wiring). However, none of the ones I've gotten from the wreckers have worked either. Does anyone know anything about the actual sensors? Using my multimeter, I have no continuity between any of the 4 wires going in and the casing. Yet, when plugged in, the air bag computer can tell whether or not it's plugged in, and whether or not it is grounded to the chassis.

Can anyone with a working system spend a few minutes checking for continuity on any of the wires going in and to the casing?

[pseudoboyfriend]

Just wanted to post a note saying that I was able to fix my Code 9 air bag problem. How? By replacing sensors and computers until it went away. Along the way, I figured out a few things that no one else seems to know (or at least won't comment on). So here I am going to dump my knowledge in hopes that it helps someone else.

First off, Supposedly there are 5 sensors. I have only found 4. 3 of them are known as the primary sensors. These are located in each of the fenders just behind the corner lights, and the third is just under the hood latch. The fourth that I have found is known as the driver's side sensor, and is located in the a pillar below the hood latch pull. I never found the passenger side sensor.

Air bag wires are twisted together in pairs, so they are easy to identify when tracing wires. You can test continuity of the wires by jumpering ends, and using a multimeter on the other ends. Test for a short to ground by testing for continuity between the wires and ground.

The backup ps for the air bag system is by the EEC in a blue box. The blue box on the right side of the driver's well is the air bag computer.

Some air bag problems are due to a worn out clockspring in th steering wheel, and can be solved easily by replacing it. A code 9 is unlikely to be the clockspring. a Code 9 is either a failed one of the three primary sensors, an open or short in the wires leading to them, or a faulty air bag computer. Replace with known good units, or keep replacing until you find some good ones.

Some people will tell you that they must all be replaced at once. This is false. You can only buy new sensors in a full set (for around $900 CDN). You can replace with sensors from a junkyard one at a time. I would suggest looking for cars that havn't been in an accident, because likely the sensors will be bad.

As always, be careful, disconnect the battery, give it 20 minutes before working on it. I suggest unplugging the backup ps as well. Remove the air bag itself if you are paranoid. but don't fear the system. It is actually very simple, and you CAN repair it if you try.

[Paul_]

I've unplugged air bags in the past with the battery hooked up, and once with the car running,

But that's just me.

[pseudoboyfriend]

Yeah I know what you mean. I see a lot of fear mongering and not a lot of useful information regarding air bags. Still a good idea to be a bit careful. But people should not fear them.