Technical FIAT 1.3 2009 AIRBAG ECU DEAD

[eeje]

I have a 2009 500 1.3 diesel with the dreaded airbag lights on, flashing miles, fuel cut off ect.

Having looked at this with Multiscan and checking all wiring I cannot connect to the airbag ECU. So I suspect its dead.

Also replaced the battery as it looked like it had seen better days.

My question is, if I buy a decent second hand airbag ECU connect this and do a proxy alignment will this sort the problem. Or is there more to it than this?.

Thank you

 

[jrkitching]

Hello and welcome to the forum.

@typecastboy has done quite a few of these. He may be along shortly.

Also, have you checked the wiring at the point where it passes into the rear hatch.. This is a very common failure point, and on a 2009 car will likely already have been repaired at least once. For some reason, failure of this section of the loom has been known to cause problems with the airbag ECU.

 

[typecastboy]

Are there any other errors coming up on other ECUs? It could well be the hatch wiring but I think it's more likely to be the ECU. As a 2009 car, you will most likely have the metal cased one. They are rarer but are still available. You should be able to swap them, do a proxy alignment and hey presto, all will be good again. If not, then the next thing to check is the hatch wiring, in fact it would be prudent to check that first. Disconnect the earth battery lead before you do. Same goes for when you swap the ECU.

Also, your main earth strap, if not been changed before, will undoubtedly be rotted out and would certainly benefit from a change. They are £4 on Ebay for better than OEM ones.

 

[eeje]

Thanks for the replies.

I’ve checked the hatch wiring and looks ok. I’ve repaired a few on Alfa Mitos so that was my first thought.

I’ll check the main earth strap as per your suggestion.

Only other fault codes are inertia function FIS, think that’s the fuel cut off message on the dash. Also there was clutch signal short or open circuit.

I’ve just fitted a new clutch pedal and clutch switch but didn’t have time to re scan or clear the fault.

Is it possible to fit the new type airbag ECU if the old metal one is in there ( did check the plugs on the drivers side but can’t remember what type it was).

 

[jrkitching]

Only other fault codes are inertia function FIS, think that’s the fuel cut off message on the dash

I remember reading somewhere that the fuel cutoff is controlled by the airbag ECU.

Is it possible to fit the new type airbag ECU if the old metal one is in there

Read this thread

 

[typecastboy]

Fuel cut off is indeed controlled by the ECU. You can't swap the ECU with the plastic top one, it's needs to be the same kind.

 

[puntodeltathema]

Rear hatch wiring shorts can fry the ECU in my experience (I'm not exactly sure why...) so it would be worth double checking before sticking a new or repaired unit in. You can get the ECUs repaired by mail order. Northern Autotech in Morecambe is the latest place I've used, good efficient service. But others are available...

 

[eeje]

Sorry for late reply.

I have now checked everything that could be associated with the airbag lights ect.

Only conclusion is that the ECU is dead.

My question is the original ECU is 51782985 Siemens metal body. The is also a 51867767.

I did read somewhere that this is the same unit with just a later software update and it was said that this would fit.

Does anyone know if this is true?

 

[The Panda Nut]

Be careful. Too many people have gone from bad to worse changing ecus

Get it professiobally tested and repaired.

Check no bad connections to wires under seats. Occupancy sensors can affect this.

 

[DanGri]

Are there any other errors coming up on other ECUs? It could well be the hatch wiring but I think it's more likely to be the ECU. As a 2009 car, you will most likely have the metal cased one. They are rarer but are still available. You should be able to swap them, do a proxy alignment and hey presto, all will be good again. If not, then the next thing to check is the hatch wiring, in fact it would be prudent to check that first. Disconnect the earth battery lead before you do. Same goes for when you swap the ECU.

Also, your main earth strap, if not been changed before, will undoubtedly be rotted out and would certainly benefit from a change. They are £4 on Ebay for better than OEM ones.

Hello Sir.
I need to buy a new airbag ecu. Do you know what numbers that has to match for it to work? Is it this: A2C53366482 or this: 5187005 (Which I think is a barcode number). Thank you!