:bang: some one please help i have fiat 500 multi-jet diesel 2008
few days back air bag light came on with message "airbag failure refer handbook"
took the car to fiat dealer he scanned the car with official fiat tool and could not find any error code at all. he also tried to scan with air bag fuse out this time error showed up but goes away once air bag fuse is re installed
also do not have any light for seat belt alarm or the alarm itself is not going on even i drive without seat belt.

please help me

Could be the battery. A low or fluctuating voltage or ampage can cause airbag lights to come up. Would often give other errors too. Try giving it a bench charge overnight.

Tried installing new battery but still same condition
Did a scan with launch x431 pro again no error at all
Tried to use launch x431 pro on friends Fiat ponto evo with airbag light the scanner did displayed few errors once erased light was out
But when scanning 500 it shows no error at all

The seat belt warning system is also not working not even showing the light in instrument cluster

Checked resistance of all equipment air bag and seatbelt all are normal
Betting all values from live data frame

Might be worth getting yourself a replacement airbag ECU. It's a 10-15 minute job to change. You can pick one up for £80 on eBay with no crash data. All of those errors come from the ECU.

Try using a program like multiECUScan which will address the airbag Ecu directly and read the codes from it. There are a lot of differences in airbag systems so what might have worked on the punto Evo isn't guaranteed to be the same on a 500

And apart from actual data from a passenger or drivers airbag, MES will be reset any codes.

Hi
Still working on it
I did installed my cars airbag ecu in other Fiat 500 year 2010 it worked fine no light or code in other car.

By the way my radio was blocked as well and was showing radio blocked / wait so left the car switched on over last night
Now showing enter code display

changed my battery to new this morning.

Now I can see the bell sign of seatbelt when key is on marr

But after 8 second all lights went off and airbag light stays on

But when I did the scan after this
Started giving code u 1733 convergence node in IC and u1733 convergence telematic node L1 &L2 Which I think relates to blue and me

Well trying to ask weather radio or blue and me can some how trigger air bag light

Yes that is the blue and me. No relation to the airbag ecu. How strange.

vatsboy said:

Well trying to ask weather radio or blue and me can some how trigger air bag light

Click to expand...

They're all on the same network so not completely out of the realms of possibility that a serious fault on one could knock out the other.

Still put it on something like MES as this is able to directly address every module in the car and just to just bring up a list of fault codes

Have you checked the integrity of the hatch wiring?

If there is a short or live feed in the loom, then all bets are off and diagnostics can't be relied on.

Nothing on MES no fault code

I had the same fault on one of my Accords, light on, plug in reader, light goes out before you've done anything and no stored codes, it was a known(with no fix) issue other than replacing the air bag ecu( In my case a brand new one as all secondhand ones had the same fault, that was pretty much the end of the car sadly). Though the light could stay off for years or just weeks.

My guess is either faulty plug/wiring to the ECU (there are two plugs) or a faulty ECU. Probably a voltage problem that the voltage or ampage is fluctuating making the error appear and disappear. For the sake of £80 I would buy a second hand one on eBay and try it. If it's the same you could always resell the ECU. Nothing to lose by trying.

Fiat service tried replacing airbag ecu from other Fiat 500 which came to them for service
Problem still exists
And my ecu works fine on the other Fiat 500 .
What are the battery specifications for Fiat 500 with multijet diesel engines

Battery I am using is DIN 45

Also received the code for the radio
Radio and blue and me working fine

vatsboy said:

Battery I am using is DIN 45

Click to expand...

Quick search shows this could well be the right type though there is several choices, the tray size is the deciding factor?
http://www.batterymegastore.co.uk/varta-c30.html

Back to the very first post, is their a connection between the lack of seat belt alarm and the airbag issue? the seat connections have been checked(both)?