Air bag light

[89whitepkg]

I had a quick question, my air bag light as been on since I bought the car. Is this normal…..or does that means something is wrong. Just wondering if I get in an accident is it possible that instead of getting the air bag, I just get hit in the face with the skeleton of a squirrel that decided to make a nest in there. :icon_sad:
Basically, is this cause for concern?

 

[Nick M]

Of course it is cause for concern. Otherwise Toyota would not have installed the warning light.

Typical problem is an open circuit. If you look in the book, Toyota calls it a "squib". Don't ask me where that name comes from. What I often found is things like Coke or Pepsi had been spilled on the yellow connector. The airbag connector is yellow, if you didn't catch that. Don't mess with it unless you have the factory repair manual, and a multi meter.

 

[jetjock]

Squib is a term applied to any small explosive device used to generate force. The squib is what deploys the airbag. You can run the diagnostics to find out where the problem lies but a light usually means there is a open connection in the plug, primary sensors, or safety sensor. For example the plug is designed to let the system know when it's connected.

As Nick said be careful working on this. You must wait a minimum of 30 seconds after disconnecting the battery before messing with things because the system has a back up power source and not waiting could (although the chance is remote) cause the squib to fire. Unless you know what you're doing you should take it to someone who does.

 

[Justin]

Unless you know what you're doing you should take it to someone who does.

Yah, an airbag is something I'll never mess with. They scare me I'll tear into anything on any car, but airbags always make me nervous

 

[89whitepkg]

I'll just take it to the dealer and have them look at it.

 

[Nick M]

There could be nothing wrong with it. Toyota had set up the ECU to register a fault if you lost battery power in the car.

 

[Justin]

There could be nothing wrong with it. .

the airbag light will also turn on if the ignition was cycled while a sensor or light was unplugged as well.

Example: some newer vehicles have 'passenger airbag on/off' indicators in the bezel around the radio. If someone is replacing their radio, and cycles the ignition with that indicator unplugged, it will throw a code.

 

[Zumtizzle]

Just Unplug the damn thing. I don't want a sensor to get tripped while working under my front end. IE Changing my relocated oil filter.

Bishop has his disconnected thats what decided me to do it.

 

[3p141592654]

The SRS system is well designed, and not that hard to troubleshoot. The biggest problem with it is the confusing documentation in the TSRM.

Start by reading the codes.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=AB&P=29

If you get a code 41 then the problem, whatever it was, has already cleared. Most likely problem is turning the ignition on with the instrument cluster disconnected.

Code 41 is basically a flag that something in the past happened to the system that resulted in a code being set, and that problem is now fixed.

All other codes (except 41) are easily cleared by removing battery power for 10 seconds or more.

The whole point of 41 is to trap intermittent problems and make sure they are properly traced and fixed. While it might seem like it is just a way to increase dealer profits, there is good engineering behind it.

Clearing code 41 takes more work though. To do it, you need to alternate grounding between terminals AB and Tc on a fixed time period of 1+/-0.5 seconds for two complete cycles.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=AB&P=31

This is hard to do if all you have are two wires in your hands. I rigged up a simple SPDT switch with three wires to make it easy. Flipping the switch back and forth alternates the grounding of AB and Tc.

 

[Nick M]

You can use a jumper wire. I have done it that way. Hitting the speed isn't hard, just a practice time or two.