Fixed my horn but SBS light won't go out

[cuparboy]

I finally tracked down the fault and fixed my horn but now the SBS warning light won't go out. I did nothing to the circuitry of the airbag but remove the red "plug" from the bag mechanism when I had the steering wheel off.

Does it need some sort "re-arming" sequence or something?

Anyone know? For now I have merely removed the fuse for the warning light as it annoys me. I have no idea if the bag is armed or not - I presume not (which doesn't bother me at all).

 

[star]

do you mean SRS or SBS, SRS is your air bag and if you removed the steering wheel with the ign on it will have a fault in the system.

 

[cuparboy]

do you mean SRS or SBS, SRS is your air bag and if you removed the steering wheel with the ign on it will have a fault in the system.

Sorry, I did mean SRS and yes, at one point, I did have the ignition on while the wheel was off - I think!

What fault will that have caused?

 

[panason1c]

Sorry, I did mean SRS and yes, at one point, I did have the ignition on while the wheel was off - I think!

What fault will that have caused?

Because you turned the ignition 'on' whilst the airbag was unplugged you have caused the ecu to think that there is a fault in the srs system......in response the ecu then disables the srs system (hence why the srs light remains on) ...........the only way to enable the system is a trip to the dealers for them to erase the stored fault in the ecu.

Until the fault is cleared the system will remain disabled and the airbag will not activate in an accident.

 

[cuparboy]

Thanks for that.

You'd think the ecu would test all the circuits every time the engine was swtiched on...

 

[jamesmc]

Because you turned the ignition 'on' whilst the airbag was unplugged you have caused the ecu to think that there is a fault in the srs system......in response the ecu then disables the srs system (hence why the srs light remains on) ...........the only way to enable the system is a trip to the dealers for them to erase the stored fault in the ecu.

Until the fault is cleared the system will remain disabled and the airbag will not activate in an accident.

The last sentence is of interest to me. I have an intermittent SRS fault but have been advised that it is the baby seat sensor (in the passenger seat base) that is at fault.
MB advised me that although the SRS light is on (sometimes) it will always fail safe. My understanding of that is that even though the SRS might be on, the bag will activate in an accident no matter if the seat is occupied or not.

 

[panason1c]

Thanks for that.

You'd think the ecu would test all the circuits every time the engine was swtiched on...

Yes, it does........every time the ignition is turned on, the ecu performs a self-test of the srs system (and also the abs braking system) and that is why you now have a problem.......when you turned on the ignition whilst the airbag was unplugged the system self-tested and detected a fault .......resulting in the disablement of the system.

 

[panason1c]

The last sentence is of interest to me. I have an intermittent SRS fault but have been advised that it is the baby seat sensor (in the passenger seat base) that is at fault.
MB advised me that although the SRS light is on (sometimes) it will always fail safe. My understanding of that is that even though the SRS might be on, the bag will activate in an accident no matter if the seat is occupied or not.

Hi,
I am happy to be corrected but my understing of srs systems is that a permanently lit srs light means that there is a fault and the airbag(s) will not activate........I think the exception is when a child seat is fitted in the passenger seat an srs lamp is then 'on' to indicate that only the passenger airbag is disabled.

'Fail-safe' to me means the system defaults to 'off'

 

[cuparboy]

Yes, it does........every time the ignition is turned on, the ecu performs a self-test of the srs system (and also the abs braking system) and that is why you now have a problem.......when you turned on the ignition whilst the airbag was unplugged the system self-tested and detected a fault .......resulting in the disablement of the system.

Why, then, does it not test when the thing is plugged in and find out that all is now OK? Is it because it has now disabled the bag?

 

[BlackC55]

Becuase it has logged a major fault and due to it being a safety related item the system must be checked by a diagnostic check to make sure all is fine.

 

[cuparboy]

Thanks .

 

[mr. shr]

cuparboy,
Do you find that when you start up the engine, SRS light comes on, goes out for about half a second, and then comes back on permanently?

That's what mine did when I had a similar prob as you.

Was told that when you start up, it does a system check. If all is well the light goes out. (As used to happen with yours before you broke it!!)
But if the light comes back on (and stays on) after a second or so, it's because it's telling you there's a stored fault which needs to be reset via STAR. (Which is basically what others have said here!)

So does your light go out for a second and then come back on? Watch closely.