Technical Airbag Warning Light

[Sasha1995]

Hi all,

I know there has been a load of posts about the airbag light being on. Let me just explain my situation:

I was changing the discs and pads all around the car and my brother spotted the brake pad wear sensor wire has been cut off so decided to reinstate it (so we disconnect the battery as we usually do) once the job was complete, re-connected the battery and the air bag light appeared on.

Any ideas whether the two events are linked? Is it worth me disconnecting/re-connecting the battery again?

Cheers,

Sasha

 

[s130]

To my knowledge the braking/ABS system is totally independent of the Airbag System. It is just coincidence.

All my experiences of the airbag light coming on have been due to the pre-tensioner connector under the either the driver's or passengers seat.

Periodically I have to disconnect, check, clean and electrical lube the connector and then clear the error down with MultiECUScan (MES).

I do not believe that the airbag system will self clear the error after multiple ignition/start/stop cycles with no faults. You are probably going to need MES or AlfaOBD or similar diagnostic kit to a) tell you what the fault is and b) to clear the error code.

 

[Sasha1995]

Hi S130,

Thank you for your helpful reply. I've disconnected both connectors, they both look pretty clean. But I will get some electrical lube. In terms of MES would you recommend the first or the second link below? Or another one?

https://www.ebay.co.uk/itm/Italian-...MIkJvnwta29QIVzd_tCh3eqQSaEAYYBCABEgLPUfD_BwE

or

Fiat Barchetta Car Engine Fault Code Reader Diagnostic Reset Repair Tool OBDII | eBay

Works with all 1996 vehicles and newer that are OBDII compliant (including CAN). No batteries required, connect the supplied OBDII cable. Motorbike Accessories. Wind Deflectors. Car / Van Accessories.

www.ebay.co.uk

Also where is the OBD plug located on a Barchetta?

 

[s130]

NEITHER OF THOSE!

For the Barchetta you need a VAG KKL dedicated interface. These are cheap and work, (unlike many ELM devices), but you then need the relevant software.

I can only really recommend purchasing kit from Gendan.

https://www.gendan.co.uk/category_161.html

and for you more specifically

https://www.gendan.co.uk/product_FESPKG.html

As the moderator on the MES forum I get to see sooooo sooooo many posts in the FAULTY ELM 327 INTERFACES DE-MYSTIFIED thread that make me very upset and angry.

The MES website has a list of recommended / approved /authorised distributers and to my knowledge nobody purchasing from these sources have ever had issues and if they did the distributer sorted it and thus no posts were made.

While I watch Ski Sunday I liken buying from not recommended suppliers a bit like going off piste! You can do, you can save money but you may be out on your own when things don't work out.

Whilst the Gendan full kit and software will cost you £125 then just two visits to a Fiat Dealer will cost you more just to diagnose and if they can't reset due to a hard fault then you will be looking at even more.

PLEASE NOTE! Some people have gone off piste with good results so they are free to recommend alternatives here.

 

[s130]

If you "B" is pre 2005 CF3 model then you will not have an EOBD socket under the driver's seat then you will also need and old 3-PIN interface cable.

 

[Sasha1995]

If you "B" is pre 2005 CF3 model then you will not have an EOBD socket under the driver's seat then you will also need and old 3-PIN interface cable.

Thank you again for your informative replies (very helpful).

 

[Sasha1995]

Hi again, finally got around to do this...

So i've ordered the relevant cables but can anyone tell me the location of the 3 pin plug for the airbag ecu? My car is a 2001...

 

[Sasha1995]

Hi again all sorry to trouble. I'm not so sure if I'm missing something but I have my correct cables (see attached photos). But where do I actually connect the cable for the airbag ECU? The attachment under the seat is a different style? Or am I looking under the completely wrong place.

 

[LeftyGreg]

Under the dashboard on the passenger side clipped to the heater

 

[Sasha1995]

Under the dashboard on the passenger side clipped to the heater

Ooo like this looks like the one if I'm not mistaken!

 

[LeftyGreg]

That is the one

 

[Simon440]

I have just used this chap from ebay -

cwautodiagnostics​

I contacted him to confirm which cables I needed, these - https://www.ebay.co.uk/itm/144489808013, then bought them from him

Crucially for me as my IT skills are limited, he offers tech support. He even offers remote access support. He logged into my laptop (numerous times), to help me get connected to the air bag ecu.
My big issue was I couldn't connect to the ecu, this ultimately was due to a USBC to USB adaptor blocking the signal.
I used my sons laptop with USB and we got it working.
I cannot praise this chap enough, it took a few days and in total a few hours to resolve all the issues and get the connection to work, the port setting etc are minefield!
All for £17.99

 

[Simon440]

NEITHER OF THOSE!

For the Barchetta you need a VAG KKL dedicated interface. These are cheap and work, (unlike many ELM devices), but you then need the relevant software.

I can only really recommend purchasing kit from Gendan.

https://www.gendan.co.uk/category_161.html

and for you more specifically

https://www.gendan.co.uk/product_FESPKG.html

As the moderator on the MES forum I get to see sooooo sooooo many posts in the FAULTY ELM 327 INTERFACES DE-MYSTIFIED thread that make me very upset and angry.

The MES website has a list of recommended / approved /authorised distributers and to my knowledge nobody purchasing from these sources have ever had issues and if they did the distributer sorted it and thus no posts were made.

While I watch Ski Sunday I liken buying from not recommended suppliers a bit like going off piste! You can do, you can save money but you may be out on your own when things don't work out.

Whilst the Gendan full kit and software will cost you £125 then just two visits to a Fiat Dealer will cost you more just to diagnose and if they can't reset due to a hard fault then you will be looking at even more.

PLEASE NOTE! Some people have gone off piste with good results so they are free to recommend alternatives here.

s130 hope you might be able to help.
I have finally got connected to my Airbag ecu but how do I know which is the correct setting in MES?
I have a 1999 car and assume I should select Barchetta 16V aspirato?
Which model is the CF3?
How do I know if my car is TRW Airbag MY97 or TRW2 Airbag (with pretensioners).
Hope that all makes sense?

 

[s130]

s130 hope you might be able to help.
I have finally got connected to my Airbag ecu but how do I know which is the correct setting in MES?
I have a 1999 car and assume I should select Barchetta 16V aspirato?
Which model is the CF3?
How do I know if my car is TRW Airbag MY97 or TRW2 Airbag (with pretensioners).
Hope that all makes sense?

If your car is CF3 (PM me your VIN chassis number an I can tell you exactly what your car is) then it will almost certainly have a 16 pin OBDII connector under the driver's seat on the cross member. It will also have pretensioners as standard. You can check this by looking at the seat rail where the beat belt buckle plugs in. If you see a round cylinder type cartridge with attached wires then this is the pretension.

If your "B" is not CF3 then do a MES Scan and it will/should detect which version (ISO code) of TRW unit you have. Again your VIN number may be able to help as well.

 

[Simon440]

If your car is CF3 (PM me your VIN chassis number an I can tell you exactly what your car is) then it will almost certainly have a 16 pin OBDII connector under the driver's seat on the cross member. It will also have pretensioners as standard. You can check this by looking at the seat rail where the beat belt buckle plugs in. If you see a round cylinder type cartridge with attached wires then this is the pretension.

If your "B" is not CF3 then do a MES Scan and it will/should detect which version (ISO code) of TRW unit you have. Again your VIN number may be able to help as well.

Thank you for the info, this is what I know so far;
My car is definitely not CF3.
It indicates TRW Airbag MY97 ( which makes sense)
And I think it says I have pretensioners.
I cleared an airbag fault easily, but am left with a pretensioners fault which will not clear, I have done as MES suggests checking connections etc but it won't clear.

But... I don't think the car has got pretensioners fitted, I have had a really good look around both seats and I cannot see the firing cylinder or any wires? and I don't recall seeing it when the seat was out.
Any ideas?

 

[s130]

Have you tried disconnecting the connectors under the seats, cleaning, checking contacts, lubricating etc. ?

 

[Simon440]

Have you tried disconnecting the connectors under the seats, cleaning, checking contacts, lubricating etc. ?

Yes tried that today, no joy

 

[s130]

If your car is CF3 (PM me your VIN chassis number an I can tell you exactly what your car is) then it will almost certainly have a 16 pin OBDII connector under the driver's seat on the cross member. It will also have pretensioners as standard. You can check this by looking at the seat rail where the beat belt buckle plugs in. If you see a round cylinder type cartridge with attached wires then this is the pretension.

If your "B" is not CF3 then do a MES Scan and it will/should detect which version (ISO code) of TRW unit you have. Again your VIN number may be able to help as well.

I have to correct myself after researching further for OP.

His chassis number and ours which is a CF3 2005 model have the same Airbag ECU and *BOTH* cars do not have pretensioners.

This may prove interesting for MES model selection as I've check just about all "B" versions and none have pretensions. That said the TRW ECU is used in other models that may have pretensioners so the whole landscape becomes rather fuzzy

If other "B" owners are reading this then you may wish to check to se if you have pretensioners. If so your VIN number would be appreciated as we may be able to unravel the mystery.

 

[Voko]

I’m a bit confused I thought the wires under the seat were for the pretensioner? Anyway mine is a 1999, with the VIS engine and has the TRW model year 97 airbag ECU. I think it has pretensioners, at least when I had an issue with one of the cables after moving the seat, it said it did and reset them using MES!

 

[Voko]

Looked under the seat, and the yellow wire is connected to a black wire via the yellow connector. The black wire heads in the direction of the seatbelt catch