Xantia side airbag light - collision sensors

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moggsy
Donor 2021
Posts: 8
Joined: 15 Feb 2021, 18:59
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Xantia side airbag light - collision sensors

Post by moggsy »

Hello again everyone,

With the aid of the helpful responses to my first post, I have made some progress ..... however, I still have the side airbag light on.

First off (and I probably should have said before, but I was only asking how to get to the side airbag controller, so it didn't seem so relevant), my case is different to many of the threads I have read, in that I am not looking for an elusive electrical fault that has appeared over time and caused the light to come on. My car had most definitely been in a (light) collision - that's why I got her cheap 20 years ago, when she was almost new :)

At the time, the airbag system wasn't part of the MOT so it didn't matter that the airbag light was on. For many years I also had an .... errrr.... sympathetic MOT place. Now I have moved countries and taken the old girl with me. She is back in her country of origin, so on the plus side at least it's easy to get parts! On the downside I need that light out to get a French MOT.

So, thus far I have :
  • replaced the steering wheel airbag (went off in the original accident)
  • cleaned all the underseat connectors, although they were spotless with no corrosion and no bad connections as the seats almost never move
  • replaced the seatbelt pre-tensioner on the driver's (left) side, this also had blown in the accident
  • replaced the driver's side side airbag controller (in the door pillar) with a guaranteed clean, code free one
The damned light is still on :shock:

If anyone can help me with the following questions, I'd be eternally grateful:
  • Having looked at the diagram of the airbags, controllers and electrics that a forum member kindly provided in response to someone else's airbag light question, it appears that everything goes via the "central" airbag controller, the one that sits in front of the gear stick under the gubbins tray. Based on this, I am assuming it's entirely possible that mine has a crash code in it. One poster said these can't be cleared, so I have acquired a replacement, guaranteed no codes in it. Anyone know if this needs to be coded to the car, like an ECU, or can I just swap it out?
  • Whilst casting about on t'internet for info on causes of side airbag light, I found a site dealing with potential fault codes. This suggested that failure in side airbag/controller OR badly mounted/connected front crash sensor would cause the same fault code, so I am supposing also the same warning light. This makes my blood run cold because post-accident, the rad and front bumper were replaced and I am now wondering whether those sensors are even there, or whether they were lobbed in the bin and the wires are just hangin' in the breeze ...... I can't find a parts diagram that includes them, so not sure of part numbers, but did find a "safety equipment" diagram which suggested vaguely that there is one at the front (below the rad possibly?) and one at either side, maybe behind the bumper? If anyone either knows where they hide, or could have a quick squint at their Xant and let me know, that'd be a huge help. I fear I may find them absent and that the faffing about inside the car was slightly superfluous :rofl2: :rofl2:
For info, she's a LHD phase 2, 2.0 Hdi 90 saloon, 1999 if you believe the DVLA, 2000 if you believe the certificate of conformity!

Any help will be hugely appreciated!
Hell Razor5543
Donor 2021
Posts: 11997
Joined: 01 Apr 2012, 09:47
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Re: Xantia side airbag light - collision sensors

Post by Hell Razor5543 »

I think the best thing you can do (if you have not already done so) is to arrange for a diagnostics session, using a Lexia clone. Then you will get the various error codes (and, usually, a reasonably clear explanation). As the Lexia is a clone of the official PSA equipment it is far better at reading the codes than generic code readers.
moggsy
Donor 2021
Posts: 8
Joined: 15 Feb 2021, 18:59
x 1

Re: Xantia side airbag light - collision sensors

Post by moggsy »

I did think about buying a Lexia clone myself, given that I plan to keep the car long-term. I don't know where I would find one out here for a diagnostics session tbh, unless I take it to Citroen and say I want diagnostics/fault codes only. I'm sure you're right re generic code readers as a friend put the all singing all dancing snap on scanner at his work on it, and the results were not that enlightening really.

Given the history with the accident and my suspicions, I want to make sure those collision sensors are actually there before I go much further! If they're missing, that is clearly going to show up as fault so will have to look for replacements. I don't want their absence muddying the waters!

I have every intention of fixing it, because the bottom line is that even if I have to throw a fair bit of money at it, I'd rather do that than spend 1000s on something else that I will almost certainly like a whole lot less than my beloved Xant!
moggsy
Donor 2021
Posts: 8
Joined: 15 Feb 2021, 18:59
x 1

Re: Xantia side airbag light - collision sensors

Post by moggsy »

Please disregard my second question - I rechecked the diagram I'd seen and discovered it's a generic safety system diagram.In response to another post, a member (thank you wheeler) confirmed that Xantias don't have front collision sensors and it's all in the central ECU/controller. #-o but Phew.

If anyone knows whether a replacement main/central ECU/controller has to be coded to the car, that'd be a big help.