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        General >> Problems >> Airbag seatbelt warning light on
        
(Message started by: shooshyneman on Jul 7th, 2010, 6:39pm)
Title: Airbag seatbelt warning light on
Post by shooshyneman on Jul 7th, 2010, 6:39pm
Fixed the abs light! Now the airbag light is on permanently. What is it telling me? wife says its because she didn't fasten her seatbelt.............
Title: Re: Airbag seatbelt warning light on
Post by lleewar on Jul 7th, 2010, 7:47pm
The airbag connector behind the air bag is generally the cause for the light coming on. Disconnect the battery for 15 mins then remove the pad and you may find that the connector has come loose. The connector goes in one way.
Title: Re: Airbag seatbelt warning light on
Post by Cosray on Jul 7th, 2010, 10:14pm
... alternatively the connector oin the airbag sensor module, which sits close to the Central Timer Module in a LHD car. It is a sturdy shiny aluminum Siemens make module sitting on a support bar, again in an LHD car under the steeringcolumn. Look for a yellow cable and connector.

Also, remove your fascia carefully, de-install your instrument cluster and give all connectors and sockets a proper clean with spray and coating.

The connectors at the rear of the instrument cluster are a source off false indications, because of corrosion and dust from the leaking vents. Mind you, most of these connctors are 10 years or older by now and never moved nor touched.

While the cluster sits on your workbench replace ALL lightbulbs!

Here's a link to some shots I took from the rear of the wheel and the data connector, looking up from the footwell, showing the various modules:

http://picasaweb.google.nl/babpic123/LocatieCentralTimerRadioInterface11jun10?authkey=Gv1sRgCOyqvbP3-_7dZw&feat=directlink


HTH
Ray
Title: Re: Airbag seatbelt warning light on
Post by shooshyneman on Jul 8th, 2010, 3:44pm
Its gone out now----all by itself !!  hope this isnt another am pm thing!
Title: Re: Airbag seatbelt warning light on
Post by Cosray on Jul 8th, 2010, 4:14pm
... in my electronics profession we have two applicable sayings:

RWT  -  Right When Tested

FNF  -  Fault Not Found

Those apply to situations where, after hours of failure, misconduct, non-functionailty and research, measuring, testing, trial-runs etc. the problem j u s t   v a n i s h e s ... without any traceable cause... leaving everyone scratching their heads, hoping the plane will fly next time.

;-))

However, in Scorpios, 10-15 years after their production date, this strongly points to corroded connectors -- and Scorpio has some 300 of them, times 10 contacts each.

My suggestion would be to pull and clean and spray and lube all of the applicable connectors: certainly on the Airbag Sensor Module and behind the Instrument Cluster.

Corroded contact play up in summer and winter due to shrink and expansion between night and day because of huge temp variations. Behind the dash these have an effect, too.

The trouble will always hit when most inconvenient.

HTH
Ray
Title: Re: Airbag seatbelt warning light on
Post by Chieftain on Jul 8th, 2010, 5:20pm
This is the problem that some cure by a gentle tap on the dash, but what part is that affecting?
Title: Re: Airbag seatbelt warning light on
Post by Cosray on Jul 8th, 2010, 8:38pm

on 07/08/10 at 17:20:01, Chieftain wrote:
This is the problem that some cure by a gentle tap on the dash, but what part is that affecting?


So true Chieftain, so true... in Scorpio's, the most recent having been produced  minimally 10 years ago, it most definitely is a rotten pardon corroded connector...

Ray
Title: Re: Airbag seatbelt warning light on
Post by Nunnspoet on Jul 9th, 2010, 8:54am
Some 4 years ago I replaced the dash and instrument cluster lights.  Whilst "looking up" how to proceed on the Site much was made of the importance of making sure that when the Cluster is removed it MUST be kept face up.

I hope this helps

Mike  
Title: Re: Airbag seatbelt warning light on
Post by shooshyneman on Jul 10th, 2010, 10:13am
Its back on again Grrrr- but this time it was on off on  as I drove over all those nasty pot holes. So I suppose now  I am looking for a bad connector. Will start bashing the dash!
Title: Re: Airbag seatbelt warning light on
Post by Mike H on Jul 10th, 2010, 11:36am

on 07/09/10 at 08:54:46, Nunnspoet wrote:
much was made of the importance of making sure that when the Cluster is removed it MUST be kept face up.


Why is that? Can't remember!
Title: Re: Airbag seatbelt warning light on
Post by Tompion on Jul 10th, 2010, 11:56am
I think it's because the damper oil in the drives for the pointers will leak out.
Title: Re: Airbag seatbelt warning light on
Post by Tompion on Jul 10th, 2010, 12:06pm

on 07/10/10 at 10:13:00, shooshyneman wrote:
Its back on again Grrrr- but this time it was on off on  as I drove over all those nasty pot holes. So I suppose now  I am looking for a bad connector. Will start bashing the dash!


On mine I am convinced it is caused by a solder joint in the panel and not a connector.
It tends not to happen in cold weather, generally in hot weather after a few miles. Pressing directly on the glass over the light will often make it go out for a while.

One day I'll get round to checking it out. I do know it takes a fairly torturous route across the dash circuit board – I’ll probably just bridge the relevant tracks with a couple of wires.
Title: Re: Airbag seatbelt warning light on
Post by Cosray on Jul 10th, 2010, 3:09pm
... connectors at the back of the instrument cluster repeat:  connectors at the back of the instrument cluster are the culprits.

They are all corroded since production date which in my case 15 years ago because of leaking vents and damp.

They will subsequently make your door ajar lights flicker when all are closed, they will stop your trip computer from responding and make your temp show - 10 degrees and the snowflakes come on in July. Tacho goes funny and cruise control disconnects erratically.

In short - the instrument cluster, unbeknownst to many, is a many facetted regulator and processor.

There are some 4 or 5 sockets IIRC, each holding several connectors. Kontakt 60 spray, Kontakt 61 and lube. Works wonders.

In my LHD the fascia can be unscrewed, then carefully pulled sideways, sliding behind and past the steeringwheel when that's fully lowered and pulled outward.

Do not know how that works for a RHD though...

The rear of the cluster cannot be reached from the floor up when in place.

When de-installed do remember to replace all lightbulbs!

HTH
Ray
Title: Re: Airbag seatbelt warning light on
Post by Tompion on Jul 10th, 2010, 3:18pm

on 07/10/10 at 15:09:32, Cosray wrote:
... connectors at the back of the instrument cluster repeat:  connectors at the back of the instrument cluster are the culprits.

That is not the problem with mine, repeat that is not the problem with mine :)

Do you honestly think I haven’t checked such a simple thing ???
Title: Re: Airbag seatbelt warning light on
Post by Cosray on Jul 10th, 2010, 3:28pm
Yes Tompion, you certainly left that impression:  

"One day I'll get round to checking it out. I do know it takes a fairly torturous route across the dash circuit board ".

Besides, you did not mention you had elimiated that cause.

Just being helpful!
No offense -
Ray
Title: Re: Airbag seatbelt warning light on
Post by Tompion on Jul 10th, 2010, 3:57pm
The airbag warning light problem has been mentioned on here before & possibly more over on the email list, where it has often been referred to as “slap dash” (as that often fixes it temporarily).
Whilst the problem may have a different cause in each case – indeed it could be a real fault with one of the components, the impression given in many cases is that the problem is with the instrument cluster or its connections rather than other components.
People with this fault don’t seem to be reporting other problems with their instrument cluster. It seems unlikely to me for those with just that set of circumstances that they would all have corrosion of the cluster connections that affected the airbag light & nothing else.
Title: Re: Airbag seatbelt warning light on
Post by Cosray on Jul 12th, 2010, 8:14pm

on 07/10/10 at 15:57:11, Tompion wrote:
People with this fault don’t seem to be reporting other problems with their instrument cluster. It seems unlikely to me for those with just that set of circumstances that they would all have corrosion of the cluster connections that affected the airbag light & nothing else.


Good reasoning Tompion, prove me wrong  ;-))

Ray
Title: Re: Airbag seatbelt warning light on
Post by Tompion on Jul 12th, 2010, 10:30pm
;D
Presumably for a poor connection to be the problem it would mean the pin has to be powered for the light to be out so first question is do you know the airbag light comes on if the pin isn’t powered (or earthed)?

By comparison the ABS doesn’t work that way – but of course the Airbag light may work differently.
The ABS light comes on if its pin is earthed, so a poor connection shouldn’t make it flicker unless there is an ABS fault.
With a permanently failed ABS warning light connection the light will not come on as part of the initial test procedure of the ABS.

Dave
Title: Re: Airbag seatbelt warning light on
Post by Cosray on Jul 13th, 2010, 3:38am
Dave, studying the Instrument Cluster diagram the ABS LED circuitry appears to be elementary.

It is not controlled by the cluster's micrprocessor and its Anode is simply on 12V, so grounding cathode will make it light up. This is done by grounding it in the ABS processor. The ABS processor and software will decide what for reason it will do that: malfunction, selftest etc. A bad connector on the cluster is not detected as this will not make it light up.

The Airbag LED is not controlled by the cluster's micrprocessor either and its anode is on 12V. Its cathode has additional transistor and Zenerdiode and voltage divider circuitry around it, expecting 5V on the relevant connector's pin 7. In fact it it behaves like a primitive bridge, expecting a balanced signal.

If that particular voltage is absent or out of range, either by an open lead, or a ground or any other disturbance the LED will light up.

In a normal situation The Airbag Module's software will make it light up in a controlled way at start, malfunction, selftest etc.

A bad connector therefore will cause the Airbag indicator LED to flicker or stay ON as long as the voltage on pin 7 is not within proper boundaries.

HTH
Ray


PS  Just tested the circuitry by pulling the connector off the Airbag Module and the LED is ON.

http://picasaweb.google.nl/lh/photo/Fq5XyeK_Rq5sBG2IboMEBfKDUfNWfohqOaQCMmYaK2U?feat=directlink

I did not venture to pull the connector at the back of the cluster though; cannot reach it without deinstalling the fascia.

HTH
Ray


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