Help required with warning lights

[JackMa]

Hi All,
I'm new to this forum and I'm looking for some help for my recent purchase, a Citroen C3 2018 MK3 Puretech Flair 1.2 petrol.
The car is relatively new and it has about 14000 miles. Unfortunately, the car has been involved in a previous accident where rear wheel, quarter panel and subframe have been damaged on the driver side. None of the airbags have deployed.
Since the accident the car has been displaying the following warning messages and respective warning lights:

- airbag or seat belt pretensioner fault,
- tyre under inflation detection system fault,
- Collision detection risk system fault,
- Automatic breaking system fault.

I have already changed all the seat belts as the pretensioners deployed on all the original ones that were installed, but the airbag light is still there. I have tried to read the error codes and clear them with a cheap OBD reader from AliExpress, which I have interfaced with a free car scanner app. The only code I can read is U1218(81), which doesn't tell me much about what's causing the issues. See images attached for reference.
I'm assuming that the tyre pressure system fault is caused by the fact that I currently have a rear spare wheel installed on the driver side, as the original one needs a new tyre.
I found this OBD reader which seems to be specific for Citroen and relatively cheap:

https://www.ebay.co.uk/itm/116564326842 ... qMQAvD_BwE

I'd like to buy an inexpensive OBD scan tool that will allow me to read the errors, understand what's causing them, make the repairs and clear the codes.
Did somebody have any experience with these OBD scan tools? Alternatively, can anyone suggest any good alternative to this?

Many thanks in advance.
JackMa

[mickthemaverick]

Hi Jack
There is a list of members with Lexia who are willing to help out. Read the info at the top of the list and then see if there is someone near you.:

viewtopic.php?p=509922#p509922

[RichardW]

It's very likely that the crash data in the airbag ECU will need to be cleared - but this can often not be done with a normal scan tool. You could try asking air bag service https://www.airbagservice.co.uk/ what's required - the lads on Salvage Rebuilds use them all the time.

[JackMa]

Thanks both for the quick replies!
I will provide some updates as soon as I have them.

[wheeler]

Yes once an airbag or pre tensioner is deployed the ECU ‘locks’ . You either need to replace the airbag ECU or as said above send it to someone that can erase the crash data from it & unlock it.
Note that the dealer tool can’t do this as officially the unit must be replaced.

[JackMa]

Thanks All for your replies. I have bought an Actia PSA XS 9780.Z5 diagnostic tool and I have managed to install diagbox on my laptop.
Yesterday I have tried to read the faults and clear some of them, but it didn't work for some of them. See attached list of faults read for the BSI and Airbag, which I haven't been able to clear.
I presume my airbag module is locked due to the accident.
Can someone please confirm if that's the case for my Citroen C3 2018 MK3? If so, I presume I will need to get the airbag control module reset?
Thanks in advance.

[wurlycorner]

It says it has detected an impact, so yes it does look like yours will need to replaced with a 'good' module, or sent off to be re-set by an after-market specialist supplier.

[JackMa]

Thanks for confirming @wurlycorner.
Changing subject, I bought an Actia PSA XS 9780.Z5 Diagnostic Tool and I was wondering if someone can help to confirm if it's a full chip or not.
See images attached for reference.
Thanks in advance.

[Kees]

No, it's not full chip!! There are transistors where should be 7 optocouplers. You have only 2 of them (the withe cubes)
In the past I had one of those, it was not possible to read all the computers in the car.
Greetings,
Kees.

This is how it should be.

[JackMa]

Thanks @Kees for the quick reply.
I got scammed then
Is there a comparison list of what mine can do VS what the full chip one can do?
Also, where can I find the full chip version?
For example, is the following a full chip tool?
https://www.aliexpress.com/p/tesla-land ... 0IQAvD_BwE
Thanks in advance.

[Kees]

https://nl.aliexpress.com/item/1005006971895315.html
This one is correct..

[JackMa]

https://nl.aliexpress.com/item/1005006971895315.html
This one is correct..

Thanks!

[JackMa]

Morning All,
some updates on my attempt in trying to solve the issue I have on my Citroen C3 MK3.
I had the crash data cleared from the airbag control module. I have then tried to clear the falut codes using the diagnostic tool I bought (not a full chip one, see images in previous post), but it didn't work and they keep on reappering:

I have noticed that from the first fault codes reading 2 of the faults have disapppeared and 2 new ones have appeared:

So I'm wondering if it's the diagnostic tool, that being a non full chip one, is not capable of clearing these codes or if it's something else. Can someone help please?

Also on a slightly different subject, I have bought 2.2 ohm resistors pack to check the airbag itself, in case that's cause of the fault.
However, when checking the resistance of the resistors with a mutlimeter I can't read anything. I'm not sure why.
Is it possible that my multimeter that can't read the resistance of these small resistors being a relatively basic and cheap multimeter?
The strange thing is that it worked when reading the resistance of a long thin wire less than one metre long, and it reported a value smaller than 2.2 ohm. So, I'm confused.
I would excluded that the resistors are faulty as I bought 25 of them, and I can't read the resistance of any.

Thanks in advance.

[myglaren]

Sounds odd. Could you string them all together and measure the combined resistance, and measure a light bulb, just to check the meter?

[mickthemaverick]

Do you get 0 when you connect the leads together? If not replace the battery in the meter and try again.