Fiat ducato air bag warning light is on…..AGAIN. (1 Viewer)

[Camper634]

For the 3rd time in less than 12 months the air bag warning light is back on the dash.The last time was 6 weeks ago when it cost me £88 with crashdata to have the module reprogrammed.I did ask the question then why has it gone again.One of the replies it could be high voltage when starting the engine.So every time since the last replacement i have turned the ignition to on and waited until the various lights went off before cranking the engine.This morning i only tuned the ignition on to check mu LPG levels and almost immediately the air bag light came on.
I am at a loss what to do next.I cant keep paying £88 God knows how many times.Has anyone please got/had this problem and found out a reliable fix?Any help greatly appreciated.

 

[Stealaway]

That's strange, I would check the connections under the seats at the first opportunity. Have you recently put anything under your seats to take with you ?

This wires under the seats nonsense keeps rearing it's ugly head. Believe me there are no wires relating to the air bad sensor or module under any seats.
The only wires under my seats are for the seatbelt lock and seat belt tensioner in the event of a crash.
The airbag module is a completely separate item and will fire off both front air bags in the event of of a collision inless the passenger one has been turned of in the menu settings .

Proove me wrong?

 

[jockaneezer]

Just out of curiosity, if you were in a substantial collision, would every airbag in the vehicle operate, or just the ones for the seats that were occupied ? I know some seats have a sensor in the squab and others would know the seat was in use as the seat belt buckle may activate a switch in the buckle receptive ?

 

[gus-lopez]

The only wires under my seats are for the seatbelt lock and seat belt tensioner in the event of a crash.

Yes & that is what they are referring to.

The airbag module is a completely separate item and will fire off both front air bags in the event of of a collision inless the passenger one has been turned of in the menu settings .

They are all linked. when you crash & the airbags are operated it also fires the seat belt tensioners & on vehicles fitted with them it fires the locking mechanism on the seat belt retractors..
In most vehicles these days it fires & locks all seat belt retractors , pretensioners front , side & roof air bag curtains.

Just out of curiosity, if you were in a substantial collision, would every airbag in the vehicle operate, or just the ones for the seats that were occupied ? I know some seats have a sensor in the squab and others would know the seat was in use as the seat belt buckle may activate a switch in the buckle receptive ?

I don't know about all vehicles but I watched one recently where a new mini was in a frontal collision & it required driver & passenger air bags, seat side air bags , roof curtain air bags, front & rear pretensioners, front & rear seat belt retractor repairs, seat covers repaired, head lining repairs. there was also something else that I had not seen before & can't remember what it was ? & the vehicle had only driver & front seat passenger yet all seat belts had fired & locked.

this is why even in a moderate lightly damaged vehicle it gets written off as the cost of repairing that lot + labour added on to the actual damage repair means it is not economic.

** just remembered . Detonators on the bonnet hinges to elevate the rear of the bonnet. Something to do with pedestrian safety?

 

[Stealaway]

Just out of curiosity, if you were in a substantial collision, would every airbag in the vehicle operate, or just the ones for the seats that were occupied ? I know some seats have a sensor in the squab and others would know the seat was in use as the seat belt buckle may activate a switch in the buckle receptive ?

There only seems to be two airbags in a Ducato. Possibly because they are not a legal requirement in commercial vans.
I can't see or understand how the seat knows it's occupied or not

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[Phill D]

There only seems to be two airbags in a Ducato. Possibly because they are not a legal requirement in commercial vans.
I can't see or understand how the seat knows it's occupied or not

Our 2012 Ducato has a pressure sensor only in the drivers seat, none in the passenger even though we have driver and passenger air bags.
The seat belt warning is only activated and muted by the drivers seat belt.
I understand that both air bags activate if in a collision.

 

[cgwcmlw]

For the 3rd time in less than 12 months the air bag warning light is back on the dash.The last time was 6 weeks ago when it cost me £88 with crashdata to have the module reprogrammed.I did ask the question then why has it gone again.One of the replies it could be high voltage when starting the engine.So every time since the last replacement i have turned the ignition to on and waited until the various lights went off before cranking the engine.This morning i only tuned the ignition on to check mu LPG levels and almost immediately the air bag light came on.
I am at a loss what to do next.I cant keep paying £88 God knows how many times.Has anyone please got/had this problem and found out a reliable fix?Any help greatly appreciated.

My Airbag ECU returned from Northern Tech (who were very helpful) repaired with a fault report of low volts, 10.8V, this happened during cranking the engine.
New battery purchased and installed. My old battery was 3.5 years old and kept charged with EHU at home and solar panel, the voltage of the old battery (12.6V) seemed OK, however unable to perform a load test.

During this downtime I have installed a switch to isolate solar panels when in transit to try and eliminate 'high' voltages. During bright sunlight, voltages of 14.8V are outputted from my solar panel controller and I have noticed various failures reports 'high voltage' on this forum of 14.6V.

Also contacted Customer Care Citroen via online form to highlight 'fit for purpose' of Airbag ECU. They phoned back the same day, but their response was disappointing, they insisted on me taking the van to a main Citroen dealer even although the van had been repaired. I think the front desk didn't grasp there was no need to go down this route and that the suitability of the Airbag ECU was at question. I have since been asked to fill in 'How did we do' questionnaire, needless to say marked down with the reasons and since tried again by dropping an old-fashioned letter.

To address the low volts, as suggested by 'TheBig1' thinking about fitting a buck/boost voltage stabiliser, two types I can see 'Input 8 - 40V, Output 12V' and 'Input 8 - 40V, Output 13.8V', not sure which output voltage (12V or 13.8V) to go down yet.

After 'Camper634' experience re Airbag ECUs, doing nothing is not an option in my opinion.

 

[Lenny HB]

After my experance with those crooks, Crash Data just dig the wallet out and get the ECU replaced by Fiat with a two year warranty. They don't check them and go on about voltage they just change them.

When my one failed within two weeks after a Crash Data repair they said my vehicle was at fault failed because of low voltage 12.6v what a load of bo**cks.

 

[BobJayne]

My Airbag ECU returned from Northern Tech (who were very helpful) repaired with a fault report of low volts, 10.8V, this happened during cranking the engine.
New battery purchased and installed. My old battery was 3.5 years old and kept charged with EHU at home and solar panel, the voltage of the old battery (12.6V) seemed OK, however unable to perform a load test.

During this downtime I have installed a switch to isolate solar panels when in transit to try and eliminate 'high' voltages. During bright sunlight, voltages of 14.8V are outputted from my solar panel controller and I have noticed various failures reports 'high voltage' on this forum of 14.6V.

Also contacted Customer Care Citroen via online form to highlight 'fit for purpose' of Airbag ECU. They phoned back the same day, but their response was disappointing, they insisted on me taking the van to a main Citroen dealer even although the van had been repaired. I think the front desk didn't grasp there was no need to go down this route and that the suitability of the Airbag ECU was at question. I have since been asked to fill in 'How did we do' questionnaire, needless to say marked down with the reasons and since tried again by dropping an old-fashioned letter.

To address the low volts, as suggested by 'TheBig1' thinking about fitting a buck/boost voltage stabiliser, two types I can see 'Input 8 - 40V, Output 12V' and 'Input 8 - 40V, Output 13.8V', not sure which output voltage (12V or 13.8V) to go down yet.

After 'Camper634' experience re Airbag ECUs, doing nothing is not an option in my opinion.

Which pins on the connectors would you connect this to?
Much like the zenor diode + resistor voltage stabiliser, which pins are the supply pins on these units?

 

[cgwcmlw]

Which pins on the connectors would you connect this to?
Much like the zenor diode + resistor voltage stabiliser, which pins are the supply pins on these units?

For my model which is a 2019 Citroen Relay, pin 1 is 0v, pin 2 is 12v on the connector nearest the engine block.

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[BillyBeckers]

Just curious. If the Air Bag ECU Sensor Module is a generically unstable unit due to repeated failures bringing on the fault light, is it not a possibility that it could fail in another mode, ie initiating the Air Bag and Seat Belt Tensioners whilst the Van is being driven? If so, surely that is good basis for a product recall / replacement.

 

[SpeedyDux]

Just curious. If the Air Bag ECU Sensor Module is a generically unstable unit due to repeated failures bringing on the fault light, is it not a possibility that it could fail in another mode, ie initiating the Air Bag and Seat Belt Tensioners whilst the Van is being driven? If so, surely that is good basis for a product recall / replacement.

I have said previously that this should be regarded by VOSA as a safety issue. I don't understand why there hasn't been a recall notice. One might speculate that FIAT/Stellantis would say there is no alternative airbag ECU module, so a recall is futile. But, has it been modified for use with the latest X290 with the digital dash? Funsters with new Ducatos might take a look under the floor to show us a photo of the module's part number, in case it has been modified by FIAT.

Reminds me of the Takata airbag global recall a few years ago. When the car industry became too reliant on one major supplier. Must have cost them a humungous sum.

 

[BouncyBoatFolk]

After my experance with those crooks, Crash Data just dig the wallet out and get the ECU replaced by Fiat with a two year warranty. They don't check them and go on about voltage they just change them.

When my one failed within two weeks after a Crash Data repair they said my vehicle was at fault failed because of low voltage 12.6v what a load of bo**cks.

I've been following this thread and mused, if you think your vans susceptible to this happening after extended layups, is it worthwhile connecting a " booster pack " to the easily accessible contacts under the bonnet? This would ensure there was ample voltage available for the start process. If the dreaded code was still triggered, then it's not a low voltage issue in the strict sense of the words, and is in fact a component issue that the user has no control over ? Tedious, I agree, but definitive.
Mike.

 

[Bustup15]

I don't get the 'low voltage' failure. Mine like others I have read on this thread failed whilst driving. So there are either multiple issues with the ecu or the low voltage is a red herring?

 

[Lenny HB]

I've been following this thread and mused, if you think your vans susceptible to this happening after extended layups, is it worthwhile connecting a " booster pack " to the easily accessible contacts under the bonnet? This would ensure there was ample voltage available for the start process. If the dreaded code was still triggered, then it's not a low voltage issue in the strict sense of the words, and is in fact a component issue that the user has no control over ? Tedious, I agree, but definitive.
Mike.

My van doesn't have layups used all year starter battery always fully topped up by solar.

I don't get the 'low voltage' failure. Mine like others I have read on this thread failed whilst driving. So there are either multiple issues with the ecu or the low voltage is a red herring?

Yep, total BS.

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[VXman]

During this downtime I have installed a switch to isolate solar panels when in transit to try and eliminate 'high' voltages. During bright sunlight, voltages of 14.8V are outputted from my solar panel controller and I have noticed various failures reports 'high voltage' on this forum of 14.6V.

My van doesn't have layups used all year starter battery always fully topped up by solar.


Yep, total BS.

I don't understand the obsession with having the engine battery charging off the solar.

Most cars cope (even with illregular use) without having solar panels keeping the battery charger up. My solar goes to the leisure batteries only. Engine battery copes fine sitting on the drive not being used for several weeks at a time. Including powering the alarm.

 

[Lenny HB]

I don't understand the obsession with having the engine battery charging off the solar.

Most cars cope (even with illregular use) without having solar panels keeping the battery charger up. My solar goes to the leisure batteries only. Engine battery copes fine sitting on the drive not being used for several weeks at a time. Including powering the alarm.

Not uncommon for a Ducato Engine battery to get dangerous low if left for more than 3 weeks, why risk when keeping it charged is so easy.

 

[VXman]

Not uncommon for a Ducato Engine battery to get dangerous low if left for more than 3 weeks, why risk when keeping it charged is so easy.

Well, if some of the above posts are to be believed it is a risk to overcharge.

As I said mine seems to last when not being used. I will plug EHU if not used for 2 or 3 weeks but from what I understand this prioritises the leisure batteries over the starter anyway.

 

[MikenPauline]

OK. Here’s the line I have had from Fiat dealer/Marquis/Benimar who have all been trying to find out why my airbag warning goes on if engine is started/left running with no one on the drivers seat.

Apparently Fiat deliver units to Benimar with bog standard commercial van seats. Benimar remove these and replace with swivel seats. What appears to have occurred is that the sensor pad got bent/damaged in the process leading to intermittent connection.

Temporary solution is to unbend the plate. Currently working ok, but van going in next week to have replacement part installed - hopefully without bending it! The real challenge was to identify the correct part number used by Benimar/Fiat - apparently there are many different ones and we had a few false starts with wrong parts.

 

[SpeedyDux]

I don't get the 'low voltage' failure. Mine like others I have read on this thread failed whilst driving. So there are either multiple issues with the ecu or the low voltage is a red herring?

Your reference to multiple issues with the ECU could be correct. Thinking about it, the chain of causation might be more complicated, involving FIAT's 12v system generally.

The sharp voltage drop you get when cranking a cold engine using a weak cab battery after the van has been unused for 10 days was my experience. That was the basis for my initial theory about the cause. There was a significant delay of a few seconds between the engine starting and the airbag warning light appearing. How might this fault be explained? The Crash Data fault code printout supported their claim that the cause of the airbag ECU module scrambling its EEPROM software was high voltage not low voltage.

The B0100-49 fault code said 14.4v.

I could not understand why the cause would be high voltage. My own observation was that the cranking voltage drops momentarily to below 10v. An old battery still managed to start the engine, so why this unexpected ECU problem with high voltage?

On further reflection, that high voltage fault code points the finger at a voltage surge from the alternator shortly after the engine fires up. A very low cab battery voltage during cranking could provoke this kind of voltage surge. I don't have any evidence to back this up, other than the time lag for the warning light to appear, and the Crash Data 14.4v fault code printout. However a swift google discovered this:

"What controls the voltage output of an alternator?

The current flowing through the rotating solenoid (rotor) is the decisive factor for regulating the output generated by the alternator. This current is used to alter the magnetic field. It is controlled by the alternator regulator based on the battery voltage, which has been measured in advance." (my emphasis)

If either the cab battery low voltage (say 12.5v) or voltage drop (say 10v) has been measured in advance, what are the chances that the alternator regulator will respond by increasing the output voltage to the cab battery immedately after the engine fires up? The initial source of the problem is the voltage drop when an old partly discharged cab battery cranks the diesel engine. The Alternator regulator measures that drop, then tries to compensate by increasing the output voltage. There follows a voltage surge that makes the airbag ECU module go inop. The dashboard warning light comes on. QED?

This still shouldn't be happening.

Just my revised 2d worth.

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[Camper634]

Your reference to multiple issues with the ECU could be correct. Thinking about it, the chain of causation might be more complicated, involving FIAT's 12v system generally.

The sharp voltage drop you get when cranking a cold engine using a weak cab battery after the van has been unused for 10 days was my experience. That was the basis for my initial theory about the cause. There was a significant delay of a few seconds between the engine starting and the airbag warning light appearing. How might this fault be explained? The Crash Data fault code printout supported their claim that the cause of the airbag ECU module scrambling its EEPROM software was high voltage not low voltage.

The B0100-49 fault code said 14.4v.

I could not understand why the cause would be high voltage. My own observation was that the cranking voltage drops momentarily to below 10v. An old battery still managed to start the engine, so why this unexpected ECU problem with high voltage?

On further reflection, that high voltage fault code points the finger at a voltage surge from the alternator shortly after the engine fires up. A very low cab battery voltage during cranking could provoke this kind of voltage surge. I don't have any evidence to back this up, other than the time lag for the warning light to appear, and the Crash Data 14.4v fault code printout. However a swift google discovered this:

"What controls the voltage output of an alternator?

The current flowing through the rotating solenoid (rotor) is the decisive factor for regulating the output generated by the alternator. This current is used to alter the magnetic field. It is controlled by the alternator regulator based on the battery voltage, which has been measured in advance." (my emphasis)

If either the cab battery low voltage (say 12.5v) or voltage drop (say 10v) has been measured in advance, what are the chances that the alternator regulator will respond by increasing the output voltage to the cab battery immedately after the engine fires up? The initial source of the problem is the voltage drop when an old partly discharged cab battery cranks the diesel engine. The Alternator regulator measures that drop, then tries to compensate by increasing the output voltage. There follows a voltage surge that makes the airbag ECU module go inop. The dashboard warning light comes on. QED?

This still shouldn't be happening.

Just my revised 2d worth.

Mine went on the blink(for the 4th time)as soon as i turned the ignition on and BEFORE I cranked the engine.

 

[BobJayne]

Just had a new airbag fitted to my Elddis Majestic (Peugeot) '68 whilst it was in for it's MOT.
Carried out by Essanjay Motorhome Specialists in Poole.
When I collected it I asked whether it was worth me taking away the old unit (B-0100 code) to send it off to Crash Data to keep as a spare. They said in their experience they wouldn't bother as they tend to fail again after a couple of months and you've lost your money as no guarantee.
They also said that as far as they're aware Fiat have realised there was a problem and have fixed it as it now has a different part number. They have had no failures in any that they have fitted an ECU with the new part number.
Only 1 year warranty with mine as it's a Fiat ECU fitted to a Peugeot base vehicle, you only get the full 2 years if fitted to a Fiat base vehicle.

 

[Phill D]

Just had a new airbag fitted to my Elddis Majestic (Peugeot) '68 whilst it was in for it's MOT.
Carried out by Essanjay Motorhome Specialists in Poole.
When I collected it I asked whether it was worth me taking away the old unit (B-0100 code) to send it off to Crash Data to keep as a spare. They said in their experience they wouldn't bother as they tend to fail again after a couple of months and you've lost your money as no guarantee.
They also said that as far as they're aware Fiat have realised there was a problem and have fixed it as it now has a different part number. They have had no failures in any that they have fitted an ECU with the new part number.
Only 1 year warranty with mine as it's a Fiat ECU fitted to a Peugeot base vehicle, you only get the full 2 years if fitted to a Fiat base vehicle.

and the part number is ???? please

 

[BobJayne]

and the part number is ???? please

I haven't seen it.
I believe Lenny HB posted a picture of his when he had it changed, and that was one of the new ones.

 

[Jimbohorlicks]

I haven't seen it.
I believe Lenny HB posted a picture of his when he had it changed, and that was one of the new ones.

Can you advise a cost please.

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[Lenny HB]

I haven't seen it.
I believe Lenny HB posted a picture of his when he had it changed, and that was one of the new ones.

here you are.

Fiat ducato air bag warning light is on…..AGAIN.

For the 3rd time in less than 12 months the air bag warning light is back on the dash.The last time was 6 weeks ago when it cost me £88 with crashdata to have the module reprogrammed.I did ask the question then why has it gone again.One of the replies it could be high voltage when starting the...

www.motorhomefun.co.uk

 

[BobJayne]

Can you advise a cost please.

I was charged £357.18 for a new Airbag ECU configured and fitted.
Penton Peugeot wanted £550.

 

[Bustup15]

Mine is currently in at North East Truck and Van for a service and Air Bag ECU. They mistakenly sent an estimate including the air bag ECU replacement which IS covered by the extended Fiat warranty.

Price difference £344 plus vat. That's paid for more than 50% of the warranty cost!

I will post more about NETV once I have my van returned .

 

[Lisa]

Mine is currently in at North East Truck and Van for a service and Air Bag ECU. They mistakenly sent an estimate including the air bag ECU replacement which IS covered by the extended Fiat warranty.

Price difference £344 plus vat. That's paid for more than 50% of the warranty cost!

I will post more about NETV once I have my van returned .

Well, good luck is all I can say. I would not leave my van with them again ever! I had an awful experience with them and the van was in a state when I got it back eventually. My advice would be to go and check on it....and if you have a tracker, check the movement on it. (This was at the Immingham branch).

 

[gus-lopez]

Well, if some of the above posts are to be believed it is a risk to overcharge.

But the voltage stated is normal running voltage?

The B0100-49 fault code said 14.4v.

My Transit runs at 14,4 v all the time the engine is running? What is the problem with Fiat?

the finger at a voltage surge from the alternator shortly after the engine fires up.

Is it a "smart" alternator fault doing it? I have plug in voltage readers front & back & can watch them when I switch on the ignition. Drops back due to glow plugs to 11,1v before i can start when the ecu has done its run through lights on ,lights off. Then crank,starts, drops just below 11v then goes 12, 12,2 , 12,8, 13,3, 14,4v & that is where it stays until you turn off the engine.

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[DT]

Maybe two weeks ago while in southern Portugal my airbag light came on together with the seatbelt warning light and the kilometre numbers started flashing. Stopped and after five minutes re started and everything back to normal. One week later had the same airbag light come on but this time we continued driving and after thirty minutes or so it went out and no issues since then. We are always on ehu so no low battery. I read as much as I could on the problem but decided to keep going until the problem returns ? Have 200 watt of solar and a battery master fitted.