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Intermittent airbag light

Stevearcade

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2003 Accord CM2
As per ***le. In the last week or so my airbag light's been coming on. It seems to be pretty random, i.e. not triggered by particular circumstances (that I've noticed). If I turn the car off and on again, the airbag light goes away for a while.

I'm guess either a faulty sensor or some loose wiring. I don't remember ever reading about this on anyone else's car. Does anyone have any experience of this and can recommend a good course of action. I imagine there are a lot of impact and roll sensors throughout the car which could make troubleshooting the issue tricky, especially as it seems to come on sporadically.

Thanks in advance for any help. :)
 
Ok, I've looking into it a bit more. Common causes are loose/faulty connections in the steering wheel itself or the system tripping as it gets odd signals from the seat belt buckle switch sensor that is intrinsically linked to the airbag circuit for pretty obvious safety reasons.

I've watched a couple of videos and from that, I've gone and undone and cleaned the connector for the airbag first of all. I'm going to keep an eye on the seatbelt light and if the problem persists or if I notice the seatbelt light go on, I'm going to clean the seatbelt buckle switch sensor (which looks like a very similar design to the ABS switch on the brake pedal, which I've fixed before. It's just a thin metal strip that is vulnerable to getting dirty and not contacting cleanly.
 
For reference, videos I watched were:

[media]https://www.youtube.com/watch?v=deO2v_ljzHw[/media]
 
and...


[media]https://www.youtube.com/watch?v=pLP8eG6_TaQ[/media]
 
I'm not sure that the airbags themselves have any link to the airbag light, don't they just receive a "fire" input from the SRS trigger system ?
 
It wouldn't be very complicated for the system to also monitor the continuity of the airbag circuit. Plenty of other sensors and actuators have their continuity monitored.
 
Jon_G said:
It wouldn't be very complicated for the system to also monitor the continuity of the airbag circuit. Plenty of other sensors and actuators have their continuity monitored.
so I've had a look at the circuit diagram and sadly ......
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it's not obvious LOL
 
Stevearcade said:
Ok, I've looking into it a bit more. Common causes are loose/faulty connections in the steering wheel itself or the system tripping as it gets odd signals from the seat belt buckle switch sensor that is intrinsically linked to the airbag circuit for pretty obvious safety reasons.

I've watched a couple of videos and from that, I've gone and undone and cleaned the connector for the airbag first of all. I'm going to keep an eye on the seatbelt light and if the problem persists or if I notice the seatbelt light go on, I'm going to clean the seatbelt buckle switch sensor (which looks like a very similar design to the ABS switch on the brake pedal, which I've fixed before. It's just a thin metal strip that is vulnerable to getting dirty and not contacting cleanly.
The SRS also fires seat-belt tensioners, and I suppose that if the system thinks that a seat belt isn't plugged in, it won't fire the seat-belt temsioner for that seat. (you wouldn't want a loose buckle smashing you in the side of your head as your head is hitting the airbag).

Without unplugging an airbag on a working system, it's not clear whether the light will come on or not.
 
I unplugged the airbag and started the car. The light was on. Turned the car off, plugged the airbag in and the light was off. Like I said, I've cleaned the contacts in the airbag connector and will monitor the situation. If it persists I'll tackle the next two commonly documented issues of the seat belt buckle switch and then then the (whatever it's called) thing that sits at the back of the steering wheel and communicates with the SRS system. Whatever's causing it, I expect it's dirty contacts on a switch/connector somewhere.
 
FYI I've also found this by putting "SRS description" in the search in the ESM.

The side airbag system also includes an occupant position detection system (OPDS). This system consists of sensors and a OPDS unit in the front passenger's seat-back. The OPDS unit sends occupant height and position data to the SRS unit. If the OPDS unit determines that the front passenger is of small stature (for example, a child) and the front passenger is leaning into the side airbag deployment path, the SRS unit will automatically disable the passenger's side airbag. The SRS unit will also disable the airbag when the OPDS detects certain objects on the seat. When the side airbag is disabled, the side airbag cutoff indicator on the instrument panel alerts the driver that the passenger's side airbag will not deploy in a side impact. When the object is removed, or the passenger sits upright, the side airbag cutoff indicator will go off after a few seconds, alerting the driver that the passenger's side airbag will deploy in a side impact.
 
Is this for our cars? What does the side airbag light look like? I don't think I've ever seen it.
 
yep 2004 CM2 in the 7th gen ESM, I'm not sure what they mean by "side airbag cutoff indicator" as there's only one indicator light shown in the SRS system circuit diagram
 
Can you get it looked at using HDS Steve? If the SRS system can be 'interrogated' in a similar way to the powertrain and ABS/VSA systems, then a stored error code would presumably point to the problem causing the warning light to come on.
 
That's good to know. Cheers fellas.
 
Jon_G said:
Can you get it looked at using HDS Steve? If the SRS system can be 'interrogated' in a similar way to the powertrain and ABS/VSA systems, then a stored error code would presumably point to the problem causing the warning light to come on.
IIRC there is an SRS menu on the HDS

yep, found the pic that I posted eleswhere

02System.jpg
 
Nice one. I'll keep an eye on it. I cleaned the contacts on the airbag connector yesterday and the problem's not come back yet. If it does I'll look into an HDS as I should probably have one of my own, given the cars age :rolleyes:
 
Stevearcade said:
Nice one. I'll keep an eye on it. I cleaned the contacts on the airbag connector yesterday and the problem's not come back yet. If it does I'll look into an HDS as I should probably have one of my own, given the cars age :rolleyes:
Did the light come back on? My light comes on I've had it turned of by garage twice it's stayed of for 1000 miles and then comes back on...

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Not come back since. I'm certain it's a dirty contact issue. I work with electronics a lot and am used to cleaning switch contacts. My gut feeling on this is definitely the contact in the steering wheel boss.
 
Stevearcade said:
Not come back since. I'm certain it's a dirty contact issue. I work with electronics a lot and am used to cleaning switch contacts. My gut feeling on this is definitely the contact in the steering wheel boss.
Is it simple to do? Is there a way to reset the light without going to the garage my reader on my phone turns of most but sods law I can help most other people but not my self with my cl9 (typical)

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