Technical 2007 X250 Ducato Airbag light issue

[Newholland Tech]

Hi ,
We are a 2 Ducato family and have a problem with wife's 2007 camper Van.
The Air bag warning light used to come on and then go off for no discernible reason , wiggling the under seat wires on the drivers seat would not either cause the light to go on or to go off if already on . No errors recorded or that I can read on my generic OBD2 scanner .
Light is now permanently on but still no faults recorded .

Seeing as we have my 2011 van parked next to it I have a ready supply of test parts so a couple of questions ....

Where is the airbag ecu located ?

What resistance should I see on the wires to the pre tensioner on the seat belt connector ?

The seat belt warning light works so I can rule that out .

I suspect the ECU but it could also be the "Pen spring" I've been told .

I presume this is the spring that pushes the connector onto the slip ring on the steering column under the airbag ?

Any help appreciated as I see little point in taking it to a dealer as they will only carry out the same checks as I can at home .

Thanks in advance

 

[rayc]

I believe the air bag ECU is on the floor where the drivers foot would be if not on the clutch. If you lift up the plastic battery cover you can see it.

 

[Newholland Tech]

Thank you.
Dead right , exactly where you said but a pain to get to as the centre storage bin has to be removed and it also has a metal cover over the top help on by 2 small cross head screws that round off easily . Then 3 x 10mm nuts hold the ECU too the floor .
More of a pain in the wife's van because it's also got a nice deep pile fitted carpet in the cab that extends into the rear that also had to come out .
Tomorrow will take the one out my van and try that in the camper.....I am now reminded why I work on huge tractors , tanks, and plant .....so much better access ;-)

 

[RS3100]

You won't retrieve any airbag fault codes with a generic OBD reader, because OBD only covers emission related faults specific to the engine and drivetrain.

A good multi-system reader or diagnostic software such as MultiEcuScan will read airbag fault codes, and on the Ducato they are actually fairly descriptive.

 

[tilerdon]

That may be a waste of time as the Airbag ECU is coded to the vehicle so they won't be recognised when you move them across.

 

[Newholland Tech]

That may be a waste of time as the Airbag ECU is coded to the vehicle so they won't be recognised when you move them across.

Brilliant ,
Thank you , on further investigation the ECU's on both vans are a different P/no so unwilling to swap them over in case I kill my one .
I found the same ECU S/H for £20 so have got that on the way but if you say they need coding to the vehicle that will probably not work either .
Is it a dealer only thing or can any decent OBD system do it ?
I have noticed various people selling new ECU's , is it the case that a new ECU is supplied blank and in affect pairs itself with the rest of the vehicle at first Key on ?

I work on 250K vehicles that steer themselves to less than 1 cm accuracy yet struggle to sort a simple air bag fault because another brand in the same parent company I work for use's ECU's that seem to be made by Mickey Mouse and Co.....;-(

 

[RS3100]

I missed the fact that you were intending to swap them over. You will need MultiEcuScan or similar diagnostic software (FiCom, AlfaOBD) to carry out a proxi alignment if you replace the ECU, but Google Ducato airbag ECU repair - there are companies such as Crashdata who can test and if necessary may be able to repair your existing ECU at a reasonable cost if it is simply corrupted which can happen if you have allowed the battery to go flat or from incorrect jump starting procedures. If the original is/can be repaired, it will be plug and play. You may still need suitable diagnostic software as above to clear error codes and I would recommend it anyway to diagnose the error(s) you currently have because you are just taking a stab in the dark right now.

 

[pwhooftman]

Hi ,


I suspect the ECU but it could also be the "Pen spring" I've been told .

I presume this is the spring that pushes the connector onto the slip ring on the steering column under the airbag ?

I presume you are referring to the 'clock spring', which is located between the steering wheel and the steering column. In contrast to my presumption also, this doesn't contain a slip ring with sliding contacts in order to make the electrical connections for the airbag & horn, but a piece of flat cable wrapped circular so the steering wheel/column can make (about) 3 turns left and 3 turns right (any more turns and that cable snaps, so i learned after installing it wrong...).

The problem could arise from the connector clicked into the bottom half of this clock spring, maybe remove the steering column plastics around the ignition and wiggle it a bit.

 

[RS3100]

The problem could arise from the connector clicked into the bottom half of this clock spring, maybe remove the steering column plastics around the ignition and wiggle it a bit.

Only after disconnecting both battery terminals and waiting for at least 30 minutes unless you fancy risking a face full of airbag!

 

[tilerdon]

You didn't by any chance allow the vehicle (not leisure) battery to go flat during the winter did you. A lot of Fiat airbag ecu faults are caused by this and will have a fault code of B0100 when connected to a suitable OBD reader. If that is the case apparently Crashdata.co.uk can apparently fix this. Mine is on its way to them today for just that purpose though I don't believe that battery voltage dropped at all during the winter as I had it hooked up to the mains all the time

 

[tilerdon]

ECU arrived back from Crashdata this morning - plugged it in - NO airbag warning light - Hooray

 

[corcai]

ECU arrived back from Crashdata this morning - plugged it in - NO airbag warning light - Hooray

How much did they charge for the record

 

[tilerdon]

How much did they charge for the record

£60 plus £6 for return delivery but they appear to be offering the service for £30 now

 

[Newholland Tech]

Been busy with work but seeing has I now have 2 ECU's i may well send one off to Crashdata to be reset .
While I continue to fault find with the other one ( the original )

 

[Newholland Tech]

Got some time today to have a look with a proper OBD scanner.
The van had 4 stored errors -
B100B
B101C
B1008
B101B
Saved these and cleared the ECU fault log .
Only B1008 and B101B returned as current faults .
I then had a play around with the borrowed scanner /programmer thing and eventually cleared the other 2 codes and nothing i could do would make them return ,wiggling and pulling wires etc all had no affect .
I was not happy this was a cure but at least everything had been checked so all trim etc out back on and time for a test drive .
Van started and no warning light so looking good.....started to drive up our drive and realised that I couldn't reach the pedals properly as the seat was right back .....moved it forwards about 2 cm and the airbag warning light came on

Back on with the scanner and only active fault is B1008 .
This is described as " first level drivers airbag resistance "

I can go into diagnostics and can see it is indeed 6.00 Ohms when the second level resistance is shown as 4.50 Ohms and when it was working correctly they were both at 4.50 Ohms ........with the pretensioners all at 2.50 Ohm each and the central front one at 2.00 Ohms

Any one know what the 1st Level Drivers Airbag resistance is referring too?
I know it should be 4.50 Ohm but that's about all .
And what is the 2nd level drivers airbag resistance referring too?

If it is referring to the airbag then why did adjusting the drivers seat affect it ? I can see why pretensioner resistance could be affected either by moving seat fore / aft or revolving it if the wires are stretched or twisted

Anyone got a fuller explanation of code B1008 or indeed which wires it relates too ?
X250 wiring diagram ?
Fully used to some of the strange Italian translations for parts and terminology but this is worse than AG stuff .......we had exhaust silencers that were called "Dampers" in the part description

 

[RS3100]

Descriptions and wiring diagrams for the SRS system are included in the last available copy of eLearn which should be in the Downloads area of this site.

I used to have a document which allowed Ducato DTC look-ups, but the USB pen got corrupted and the document is no longer available

This web page suggests B1008 and B101B relate to the clockspring:

https://www.husbilsklubben.se/forums/threads/airbaglampan-lyser-ibland.102388/

It's Swedish, so you'll need to use Google Translate or similar. If you can't access it, it relates to a Ducato with those two DTCs and was fixed by replacing the central steering module including the clockspring.

The only other thing I can find relates to a Driver's airbag 1st stage circuit resistance above threshold on the Ram Promaster (Ducato as designated in N. America). Again, this points to checking the squib connectors at the clockspring (steering control module) and the wiring between the clockspring and the SRS ECU.

Could it be that you tugged at the steering wheel whilst moving the seat?

Can you clear the codes again and reproduce them by moving the steering wheel or the seat? It may help locate the area of the fault.

 

[Newholland Tech]

Descriptions and wiring diagrams for the SRS system are included in the last available copy of eLearn which should be in the Downloads area of this site.

I used to have a document which allowed Ducato DTC look-ups, but the USB pen got corrupted and the document is no longer available

This web page suggests B1008 and B101B relate to the clockspring:

https://www.husbilsklubben.se/forums/threads/airbaglampan-lyser-ibland.102388/

It's Swedish, so you'll need to use Google Translate or similar. If you can't access it, it relates to a Ducato with those two DTCs and was fixed by replacing the central steering module including the clockspring.



The only other thing I can find relates to a Driver's airbag 1st stage circuit resistance above threshold on the Ram Promaster (Ducato as designated in N. America). Again, this points to checking the squib connectors at the clockspring (steering control module) and the wiring between the clockspring and the SRS ECU.

Could it be that you tugged at the steering wheel whilst moving the seat?

Can you clear the codes again and reproduce them by moving the steering wheel or the seat? It may help locate the area of the fault.

Thank you ,

Had a busy day fixing diggers and dumpers today so no chance to look at the van .

Asked a wizz with building performance Fords and sorting electrical gremlins and he reckoned the the squib connectors were a good place to start .

I think you are correct in saying I may well have pulled on the steering wheel as I adjusted the seat , thing is the code won't clear now so can't try doing it again.

I think it may well be worth just replacing the clock spring / steering module just to rule it out.

That's the current plan I think ....there is seemingly a spurious wire going from the area that has been grafted on disappearing under the dash , (probably horn I think) that I'm going to snip and see what stops working .

Guy who built the camper did a fantastic job as it's better made inside than most of the flash new ones we looked at ......but I'm not sure he is a good electrical or mechanical engineer......or maybe years of building rally cars and restoring WW2 Vehicles has made me have OCD when it comes to such things

 

[Newholland Tech]

Is the Clock spring a Fiat only part ? Local factors can't cross reference with any non genuine parts and from Fiat it seems to come as an assembly with both stalk switches .

 

[RS3100]

...from Fiat it seems to come as an assembly with both stalk switches .

That's certainly the inference in the Swedish forum post I linked to above, although I haven't checked ePER. You can do that from the forum link in the title bar.


I would check and clean the contacts and the wiring continuity though before going down the main dealer route of just throwing new parts at a problem until they either fix it or give up.

 

[Newholland Tech]

Agree with the comment of throwing parts at a problem . I spent a good while training new Techs that you don't replace parts until you can prove the fault .
Given the price of a new one that only comes with the switches I don't want to just fit parts but this is an early 2007 / 2008 build van and we need it sorted .....my 2011 van has a much more robust clock spring design and better quality multi plugs so it was obviously an issue and warranted a change ....I know and deal with Fiat Family products in other industries and they don't change stuff for no reason .
Idea of changing for a new clock spring is to eliminate a problem further down the line as this seems to be a common issue and we plan on being in some fairly remote locations with the van in the future .