Passenger side carpet removal / airbag fault

[tontonjon]

Hello again!

Now the suspension strut is mended the airbag fault message has reappeared.

There are two possibilities: the airbag fault message used to appear when I pressed the horn section of the steering wheel, so I thought "comms unit". However, the fault diagnosis on my mechanic's new computer says that the fault is in the driver's side pretensioner. So, under the seat to locate the dodgy wiring and I think that I have found it, except the absence of the fault message was short lived! One journey OK, the next journey and back comes the fault.

A quick search on this forum suggests that the next place to try is under the passenger side carpet as there is a second block of joints there that several others have successfully fiddled with to clear the fault. It is worth trying this as I have time tomorrow and the car has its MOT on Monday, so if the fault is the comms unit and not the connections I can get my mechanic to change it at the same time as the MOT. However, I can't work out how to remove the carpet!

Other messages state things like "peeled back the carpet" - but how? And where is the joint that I'm looking for? I am guessing it's the lump just underneath the front of the passenger seat, but before I damage something can someone give me an idea of where to start "peeling", please? And do I need to take out the passenger seat first?

Jonathan

[GiveMeABreak]

Jonathan - it would help if I had your VIN as I can't tell which of the 3 versions of C5 you have from your avatar section or what year etc.

[tontonjon]

Sorry!

Mk1 2.0HDI RHD.

Profile updated.

[GiveMeABreak]

The diagram below shows the carpet sections and components in case that helps.

Normally, for removing he entire carpet, they would suggest removing the following:

The front seats
The rear seat cushions
The centre console
The fascia
The heater unit

But looking at the second diagram, you may be able to get away with just a part of this in order to locate the wires. They may be hidden under some polystyrene foam under the carpet - so remember to check there too.

Remove : (on each side) :
The front door aperture lower trim (1)
The centre pillar lower trim (2)
The rear door aperture lower trim (3)
Unclip the carpet ( 4) (at "a").
Remove :
The bolts (6)
The harness bracket (5)
Remove the floor carpet ( 4).

[wheeler]

the fault diagnosis on my mechanic's new computer says that the fault is in the driver's side pretensioner. So, under the seat to locate the dodgy wiring and I think that I have found it, except the absence of the fault message was short lived!

The seatbelt pre tensioners are in the inertia reels in the B pillar on the mk1 C5 so no under seat connections, older citroens used to suffer from under seat connection problems as the pre tensioners were in the stalks.

A quick search on this forum suggests that the next place to try is under the passenger side carpet as there is a second block of joints there that several others have successfully fiddled with to clear the fault. It is worth trying this as I have time tomorrow and the car has its MOT on Monday, so if the fault is the comms unit and not the connections I can get my mechanic to change it at the same time as the MOT.

Other messages state things like "peeled back the carpet" - but how? And where is the joint that I'm looking for? I am guessing it's the lump just underneath the front of the passenger seat, but before I damage something can someone give me an idea of where to start "peeling", please? And do I need to take out the passenger seat first?

The connectors that can cause problems you are talking about are under where the passengers feet would sit however if these were the problem it logs a fault with the drivers airbag not the pre tensioners.
To access them anyway you need to remove the plastic trim on the sill & peel the carpet back there, there is a big white polystyrene block you lift out & there are 2 x 2 pin connectors there.

[xantia_v6]

I would be wary that a generic code reader may be giving a misleading code.

[tontonjon]

Thank you all. Luckily, the fault was not present during the MOT and has not come back since I poked around on the top of the carpet to try and locate the connectors. I think I might leave be for the moment: taking the seat out was easy enought, but I don't want to again just yet! There is a cable that goes across the seats that connects to the seatbelt buckle either side of the handbrake: is this to detect that the seatbelt is attached? Fiddling with the wire set off the the airbag fault.

Fault codes as follows:

0802 Driver's level 2 airbag igniter open circuit.
006F Passenger's airbag deactivation not defined.

Not sure about the second, but it occured after I switched off the passenger airbag and then back on again.

Anyway, for the moment I don't need to do anything, but I know where to start when I am at a loose end one day.

[GiveMeABreak]

You need to be a bit careful as these have Pyrotechnic seat belt (pre-tensioners) that have explosives in - you shouldn't really fiddle with the wires unless the battery has been disconnected for at least 10 minutes to be on the safe side. The wires to the seats will be for the side airbags in the seats, the wires to the central seat belt buckles will be for the pre-tensioners and probably all tied into the Airbag ECU. So when you get around to the passenger side again make sure you disconnect the battery first and wait a bit before checking the connections.

[wheeler]

Fault codes as follows:

0802 Driver's level 2 airbag igniter open circuit.

This fault is for the drivers airbag circuit meaning the connections in the passengers footwell are a high possibility of being the problem, the original post said it was a fault with the pre tensioner.

[tontonjon]

I was relying on the advice of my mechanic: the original fault code he cleared following the airbag fault warning on the car stated the pre-tensioner fault; the most recent one was different, stating the above. The first has not reoccured since I hard-wired the cables under the seat. It may be that there are two faults separately causing the same message.

[tontonjon]

So when you get around to the passenger side again make sure you disconnect the battery first and wait a bit before checking the connections.

I shall! Thank you.

[wurlycorner]

Yep, those current faults aren't seatbelt pre-tensioner related.