It's all my own fault-I changed a fuse under the glove box in our 2002 Ducato Murvi Motor-Home with the ignition left on and the next thing I noticed was the air bag warning light glowing at me-the first thought I had was "that looks expensive"

After an hours labour and some checks my local Fiat garage thought that it could be the Air Bag ECU were but were not 100% sure without some further hours of checking. They could not check the ECU directly for a fault so I sent away for a second hand replacement ECU from Germany on EBay which was fitted today. The warning light stayed on! Fiat say they need to do some more hours of testing-although they did check the seat belt pre-tensioners today and they were OK.

Could the power surge have caused a problem in another part of the air bag circuit or is it more likely that my second hand ECU is also faulty?

Have they scanned it? It is possible, but rare for an SRS ECU to fail. The most common fault on the early models was high resistance on the LH airbag. Disconnect battery, remove glovebox, unplug air bag (2 connectors), clean and tighten (wire end) terminals, refit, test.

Thanks for your reply Arkk-Do you mean disconnect the left hand air bag? I think our van just has a driver's air bag on the steering wheel. I'm not sure if Fiat scanned the ECU

listy100 said:

Thanks for your reply Arkk-Do you mean disconnect the left hand air bag? I think our van just has a driver's air bag on the steering wheel. I'm not sure if Fiat scanned the ECU

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If you have a double seat in the front the center seatbelt recoil connector is pretty vulnerable. You can put a 2.2 ohm resistor in instead of the recoils and airbag to rule them out. Definitely worth getting a kkl cable and fiatecu scan to check the codes yourself.

Only have 2 single seats and both seatbelt pre-tensioners have been checked out. Could a power surge have affected the clock ring behind the steering wheel? Fiat electrician says it's not possible to check the ECU directly..

It isn't usual to cause a fault simply by changing the fuse, key on, or off. We often have vehicles in that have had a flat battery, the airbag light comes on when trying to start with a flat battery, NOT on jump starting. Usually, we simply connect scanner, delete code, and problem solved. Some vehicles, you can delete the code by disconnecting the battery for 20 minutes.
What fuse were you changing? You might find that when the fuse blew, was also when the airbag fault occurred. I would take it to a local auto electrician (one that has a scan tool), and get them to check the system before replacing an airbag ECU.

Thanks for your feedback Arkk. Thing is, I took this fuse out a few times to try to solve an unrelated problem (don't ask), and on older Ducatos the fuse in question also feeds the air bag circuit-so I found out later. Fiat technician says (with older Ducatos) he cannot tell where the fault is when he plugs in the diagnostic tool-just comes up with a "general fault".
Is a scanner a different diagnostic tool?

Is this a 94-02 model or 02-06? Either way fistecuscan or multiecuscan as its now called can read the dtcs from allen breed and siemens airbag units. The free version will do it and you can get the cable for well under a tenner.
http://www.ebay.co.uk/itm/VAG-GROUP...ent&hash=item337bdfb324&_uhb=1#ht_4887wt_1168

Cheers for that moodrater-it's a "51" registered van and I know from the serial number on the ECU that it's a Siemens unit. Will this plug directly into the unit and determine if it's faulty or not?

Dont keep swapping ECU's like there cups of tea

Its sound advice when we keep saying

Get a Cheap KKL/vag com cable with adaptor

Get a Free Edition of Fes/Mes and Find out what the airbag ECU actually thinks is wrong

Could be the beloved low battery
it could pick up a dead airbag detonation pack - who knows
But fes will tell you

Ziggy

Don't know what you mean here Ziggy-what's a "free edition of Fes/Mes"?

Listy

fiat ecu scan / multi ecu scan is what he means 51 plate is 2001 is it you probably need a 3bpin adapter cable to connect to that one

Thanks for all your feedback, much appreciated-I've downloaded the free software from multieuscan, ordered the interface cable (KKL/VAGcom), don't know about the 3bpin adapter cable but I'll do some searching...

So, I'm hoping this bit of kit will identify the cause of my air bag light. Sorry about the scepticism but 2 garages and 3 hours of labour couldn't!

listy100 said:

Thanks for all your feedback, much appreciated-I've downloaded the free software from multieuscan, ordered the interface cable (KKL/VAGcom), don't know about the 3bpin adapter cable but I'll do some searching...

So, I'm hoping this bit of kit will identify the cause of my air bag light. Sorry about the scepticism but 2 garages and 3 hours of labour couldn't!

Click to expand...

http://www.ebay.co.uk/itm/Fiat-Alfa...iagnostic_Tools_Equipment&hash=item2575d64446
http://www.ebay.co.uk/itm/Multi-Fia...iagnostic_Tools_Equipment&hash=item416b0fbee5

By all means go to another mechanic but don't expect much for 20 quid. If you ask in the newbie section there might be someone in your are with fiat ecu scan whos help you out for free or for the price of a few pints.

Good plan!