Airbag Lights and OBDII codes

Do 1st Gen Tacomas report airbag fault codes via OBDII? My ScanGauge II doesn't detect anything.

The airbag light on my 1996 Tacoma stays on continuously for the entire duration of the trip. When this started a few months ago, it happened once every 10 trips. Gradually it has gotten worse so the light appears every 2nd or 3rd trip. It never flashes, just stays on continuously.

As far as I know, the airbag has never been serviced by a shop. I know airbags are dangerous stuff, and I hate to fork out lots of cash taking it to a shop. The truck is only worth about $1500.

 

Going by memory here, I was not able to get the SGII to recognize air bag faults.

I was able to find the fault using the Toyota TechSTream software program (same thing dealer uses) to find my issue.

Start simple and look for bad connections on any of the sensors. Unplug them and plug them back in. Any wireing that is bright yellow is used only for the SRS (suplimental Restraint System).

If your light is on, then the SRS system is dead, the air bag(s) wont come on in a crash.

You won't hurt yourself or the system checking the connections, but if it gives you piece of mind, disconnect the battery and then trurn on the headlights to bleed any residual voltage from the electrical system.

More often than not, the culprit is a bad connection. Start looking for those connectors and wiggle/disconnect them. Be warned, the connectors used for the SRS system are usually a double safety, it may take some head scratching to get them apart.

 

Thanks, do you recall where the bulk of the sensors and connectors are located? Is it under the dash/stereo?

 

Doubtful.

Not a Toyota expert, but on that generation of Miata the airbag brain is on it's own. Your 'codes' are by the airbag light flashing. If the light is on solid, it's the brain that's dead.

If you can locate the brain and disconnect/reconnect the power source you might get lucky. More likely not. There was a thread the other day with a link to a vendor who rebuilds the brains for a reasonable price.

Edit: Found it. http://www.tacomaworld.com/forum/1st-gen-tacomas/355013-good-bad.html Post 6. koditten has already replied in this thread too............

 

There will be one on the core support, there will be sensors on top of the frame, near the front of the engine compartment. There should be a couple attached to the seatbelt retractors, those are hard to get to, have to pull the interior panels, there is the air bag connectors, but those are pretty safe and don't usually fail. There is the junction where they all meet the ECU, located on top of the transmission hump. Those are a bitch, but again they are safe and are not prone to failure.

I don't remember if the seats in your truck have sensors, but often there is wires under the seats for the air bag sensors. These are the ones that are most prone to issues. People cram all sorts of stuff under their seats.

The ones under the hood and under the seats are the ones that can give you the most issues. Also check that the wires coming off the connectors are still good. The sensors attached to the frame can corrode.

Air bag systems are pretty "dumb". The SRS ECU does a check every time you start the truck. If all sensort "test" good, the light turns off and stays off. It is one of the few systems that does not require a scanner to turn off the light. Fix the problem and all is good.

 

Ha, Ha. I was just gonna link that thread. Thanks for saving me some work.

 

Thanks for the suggestions. I will check the connectors.

How do the sensors function? Can they be checked with an ohm meter?

 

What does it mean when the light blinks 7 or 8 times and turns solid?
also some times the light will blink for more then 5 minuets then turn solid?

 

I was the OP of this thread -- as of a few hours ago, I'm a little scared to keep driving the truck.

My airbag light problems went away for a few months and resurfaced recently, same behavior as above. TONIGHT, however, I was driving home and thought to myself, hey, the airbag light appears dimmer than usual. About half a mile later, it went out completely. I stopped at the post office briefly, turned the engine off, and the airbag light didn't fire at all when I turned the key over again, like it should. Instead, it reappeared solid after a mile of driving -- first kind of dim, then progressively brighter.

I get back to my street and now the Airbag light is flickering and going on/off very erratically. As far as a light bulb goes, this behavior is consistent with a very loose wire or a failing power source, but I'm sure it's deeper than that. The light went off again as soon as I pulled into the driveway.

My fear, if the computer module is failing, is unexpected airbag deployment while driving down the road. Not sure what to do. I hate the idea of dumping money into it considering it's worth about $1500.

 

I understand your concern. I *think* the failure mode is to not fire at all if there's a fault, but that's real easy for me to say from where I am - it's not my face that it's going to blow up in.

You could remove the airbag completely. I don't know if that's legal or not, but it wouldn't blow up on you if you did that. Easier still, there might be a fuse you can pull that disables it.

 

This morning I went out and fired the truck up. Not just once, but probably twenty times, hoping the Airbag Light would stay on or do something erratic like last night. No luck, the light was functioning normally and went out when expected.

I shorted the pins in the diagnostic head to read any airbag codes. The airbag light will flash the codes in patterns so you can get the numbers. No codes detected -- probably because the airbag light was firing correctly. I called my mechanic and they're too busy to check it out today. He said the codes should be stored in memory. I asked how long of a memory and he thought maybe 90 days unless the battery was disconnected.

Is this true? How is that memory accessed?

 

Hmmm, this seems to be a common issue with these trucks. My airbag light has been on ever since I bought my 04 double cab. It just slowly blinks though and nothing more. Tried to find a code for it but none of the readers I have used picked anything up. On the fence with what to do now.

 

In your case, it should be pretty easy (I think) to get the codes by shorting the same two pins in the diagnostic head. Then you watch the airbag light flash patterns to tell you the airbag code. Consumer grade OBDII readers will not work. The process is pretty well laid out in your service manual if you have a copy. Otherwise, check the web for a PDF copy.

My problem is I can't get the Airbag Light to remain on at the wrong time, if you know what I mean. A real mechanic may have the same struggle, which means it's going to cost me a lot more to diagnose.

 

OK boys, I captured on video the airbag light fading on and off. It did this about 10 consecutive times this evening. Now, the light won't came back on at all. Before the light went away, I managed to obtain a DTC 31 diagnostic code.

Unless it's a wiring problem from the battery, this points to a bad airbag module. Not a good sign. This truck may be on its final legs if it won't be economical to fix.

Notice how dim the Airbag light is compared to the others.
https://www.dropbox.com/s/qc3d8cj9ga06rqy/VID_20150519_214047187.mp4?dl=0

 

I have a 1996 Taco, that had the Airbag light problem. The 1st thing I checked was the wires above the floor under the passenger seat, but no luck. Went and checked all other places as suggested by others and still couldn't find the problem. The light went off for a while and came back on last month. Yesterday, tried to find the problem again so I started with the wires under the seat. As soon as I touched the wire, light started to flicker off-on-off. Now I know the problem is there. Later I wanted my Wife to see where the problem was but I couldn't get the light to flicker or go completely off (Same as the 1st time). After a while my wife was able to wiggle the wire just right and the light went off. My advice to others: The wire under the seat is the easiest fix that you can do or eliminate, just pull the wires apart and reconnect to see if the problem is there.

Remember! I was not to able to diagnose it twice. KEEP WIGGLING!

 

The airbag deployment system also has its own battery. In case of severe impact to the front of the vehicle and the regular battery is damaged. I'm not sure how long the airbag battery holds a charge though. I wouldn't want to be connecting an Ohm meter without finding out for sure.

 

Where is this battery?

 

http://www.airbagcenter.com/airbag_light_is_on.aspx

Maybe this will help.
I don't know where they put the battery backup. Sorry. It looks like when the backup battery fails the abs light flashes.