Technical air bag light problem again

[broadis1977]

just wanted to pick your brains, i have a fiat grande punto 2008 1.2. The air bag light has come on and code says front impact sensor (driver).
i have looked for the sensor by bumper etc but cannot find one.
I have read that this could be the clockspring would/could this be right. i have also noticed that the steering wheel audio controls do not work at all.

Any info gratefully received. As to whether there is a front impact sensor or if the clockspring could cause this code etc.

many thanks in advance.

lee

 

[varesecrazy]

So..what code..??

Did the wheel buttons work before the fault light came on..?

Charlie

 

[g8rpi]

just wanted to pick your brains, i have a fiat grande punto 2008 1.2. The air bag light has come on and code says front impact sensor (driver).
i have looked for the sensor by bumper etc but cannot find one.
I have read that this could be the clockspring would/could this be right. i have also noticed that the steering wheel audio controls do not work at all.

Any info gratefully received. As to whether there is a front impact sensor or if the clockspring could cause this code etc.

many thanks in advance.

lee

If the steering wheel controls don't work it is highly likely to be the clockspring causing both faults. I'd change that first. What were you using to read the fault code? Some readers and databases have errors in translation of code to fault description.


Robert G8RPI.

 

[broadis1977]

I'm using the launch crp123 I think it is. So a clockspring could cause both problems. Audio controls on steering wheel and airbag light.
Many thanks for the response.
Do clocksprings need to be coded to car or is it just swapping old for new/used.

 

[broadis1977]

Don't know really about buttons working before. I bought car with both problems already there. Have to check code when I get home but it deffo said front impact sensor ( driver ) .

 

[varesecrazy]

AFAIK.. they are not coded..

So well worth trying a cheap teplacement as a first thing.

 

[broadis1977]

Think that will be my first port of call. Try a second hand one first. Will try and get hold of one first lol.

 

[g8rpi]

I'm using the launch crp123 I think it is. So a clockspring could cause both problems. Audio controls on steering wheel and airbag light.
Many thanks for the response.
Do clocksprings need to be coded to car or is it just swapping old for new/used.

Hi,
No coding required when changing the clock spring, it has no electronics in it.
Disconnect the battery (both terminals) and wait 10 minutes before doing any work on the steering wheel, airbags or clockspring.
The airbag ECU stores a charge so can still set the airbag off even with the battery disconnected if you don't wait.
You will have to reset the faults though, or possibly try 3 start stop cycles.


It is possible that the airbag fault is something else and the previous owner/mechanic broke the clockspring while fault finding, but you need to change it to fix the SWC anyway so may as well do it first.


Robert G8RPI.

 

[broadis1977]

Many thanks will try and get hold of a used one and give it a try. Lee

 

[broadis1977]

have tried new clock spring to no avail codes reset but problem still present any ideas where to look next. someone on another forum found luck with the cable under the battery tray, what needs to be removed to actually locate the front impact sensor what is its exact location.

many thanks again.
lee

 

[g8rpi]

Do the SWCs work now at least?

Robert G8RPI.

 

[broadis1977]

Nope think I've bought a dud clockspring because I've just noticed that the horn does not work either on either clockspring. Think it's all pointing to the clockspring g might invest in a brand new one will have to phone fiat up see how much they are. Not cheap I expect lol.

 

[broadis1977]

just ordered another clockspring unit for the punto, whilst waiting for it to arrive i reconnected the old one and now noticed that the horn, airbag light on and steering wheel controls dont workd at all, deffo think im heading in the right direction with new clockspring will let you know if it all works when it arrives.
just to add the used unit i bought had a different part number so that might be something to do with that one not working or it was dud.

 

[broadis1977]

Just replaced like for like clock spring. Audio controls and horn now work fine. Airbag light still on and still saying b0117 front impact sensor (driver) any ideas can't even see a front impact sensor. 2008 grande punto 1.4 petrol dynamic.
Have tried clearing it but once cleared returns immediately and light does not go out.

 

[Bernievarian]

Hi,
Disconnect the battery (both terminals) and wait 10 minutes before doing any work on the steering wheel, airbags or clockspring.

Hi Robert, I disagree with that, disconecting the negative (earth) is all that you need.

For greenhorns: Why negative ? Because when you're unplugging this port, the spanner you use can touch ANY vehicule body part (unless a positive port O-C !) without dammage/spark/potential explosion etc.

The internal capacitors on various Contollers will eventually (self) drain out and you'll be safe to work on airbags or clockspring; but keep in mind that electrostatic can also trigger the airbag stuff !!! Not stupid to wear an earthing wrist...

Regards, Bernie

 

[g8rpi]

Hi Robert, I disagree with that, disconecting the negative (earth) is all that you need.

For greenhorns: Why negative ? Because when you're unplugging this port, the spanner you use can touch ANY vehicule body part (unless a positive port O-C !) without dammage/spark/potential explosion etc.

The internal capacitors on various Contollers will eventually (self) drain out and you'll be safe to work on airbags or clockspring; but keep in mind that electrostatic can also trigger the airbag stuff !!! Not stupid to wear an earthing wrist...


Regards, Bernie

Hi Bernie,
The reason for disconnecting both terminals is to reduce the possibility of accidental re-connection. The lead take a "set" and even if you have moved it out of the way, it can move back on it's own and re-connect. If you disconnnect both positive and negative it reduces the chances considerably. There is also the (small) chance that contamination on the battery top could provide enough current to chassis to keep the airbag capacitors charged. Ideally you should remove the battery completely, but that is going to extremes. You are correct, and give the right reason why, that the negative should always be disconnected first and connected last.

Robert G8RPI.

 

[Bernievarian]

Hi Robert,

as a precautionary measure I must agree with you; those damn huge leads tend to come-back in place. I have more doubt about the current flowing thru the contamination !

Anyway, completely removing the battery is NOT excessive !

- it will free some valuable "room" (eg for tools on the battery tray ;-)
- good opportunity to inspect the cabling/earthing
- perfect time to clean the battery ports
- clean tray from debris/dust/leaves etc.
- have the optimate hooked-on to keep the battery well charged
- ...

What do you think of the statics and airbags ?

Regards, Bernie

 

[g8rpi]

Hi Robert,

as a precautionary measure I must agree with you; those damn huge leads tend to come-back in place. I have more doubt about the current flowing thru the contamination !

Anyway, completely removing the battery is NOT excessive !

- it will free some valuable "room" (eg for tools on the battery tray ;-)
- good opportunity to inspect the cabling/earthing
- perfect time to clean the battery ports
- clean tray from debris/dust/leaves etc.
- have the optimate hooked-on to keep the battery well charged
- ...

What do you think of the statics and airbags ?

Regards, Bernie

Hi Bernie,
Funnily enough I've worked with devices similar to airbags before, both at work (aircraft fire extinguisher squibs) and on the big black car in my avatar. Typical aerospace devices are tested to NOT fire at 1V, 1A 1W (they are, surprise surprise, 1 ohm devices) applied for a minute or more. These are not easily set of by static but anti-static precautions are taken while working with them. I think airbag components are more sensitive, but have no reliable data. Here is a practical test of similar "e-matches" http://www.emcconsultinginc.com/docs/ematch1.imm.pdf which shows static can ignite them but it seems the items tested were more the type used with fireworks. I would say yes, human static could set off an airbag if the terminals were touched.
Use sensible static precautions (resistive wrist strap is ideal, at least touch bare metal connected to chassis before touching components) and don't touch exposed terminals.
Negative battery terminal to ground contamination can be significant, battery acid and corrosion products are conductive.


Robert G8RPI.

 

[broadis1977]

Cool. Airbag light still on though pmsl.

 

[g8rpi]

Cool. Airbag light still on though pmsl.

Sorry we got off topic a bit.
I don't know the GP (I've a Croma) so can't help with the sensor location. Have you downloaded a copy of eLearn for you car? It on the Forum
https://www.fiatforum.com/downloads.php?categoryid=20


This may give a better idea of the location. If you get a later version of ePer it may tell you (by VIN) what sensors should be fitted to your car. The code reader you are using is not Fiat specific so the fault description might be slightly misleading. If you are near Cambridge I can run Multiecuscan on it for you.


Robert G8RPI.