Buy Lexia Clone Tool ('Full chip, revision C') on eBay for your Windows laptop for full diagnostic and configuration capabilities on the Citroen C3.
Read all the topics below and still got a question about lexia/diagbox? ask here - Lexia and Diagbox Questions.
Lexia and OBD Diagnostics
While fault finding electrical or electronics faults on the Citroen C3, you will often find 'fault codes' or 'P codes' mentioned as these are the logs of the faults detected by the onboard computers that run the Citroen C3 engine management systems. Not only are engine related faults stored, but all the other computer systems diagnostics are available including the automatic gearbox, ABS/ESP, BSI, radio coding, power steering ecu (ePAS ECU), MAF, keys, alarm, immobiliser, air conditioning, lighting, eco mode and abnormal sensor inputs including lights, wipers, horn and cruise control.
The hardware and software solution of the past used by Citroen dealers to access, interrogate and change the settings in the Citroen C3s onboard computer systems was called 'Lexia 3'. The later revision revision of the software is called 'Diagbox' and is designed to work with previous models and the later, more advanced post 2010 models. The hardware interface is produced by Actia and this links the diagnostic port on the car with the USB port on the Windows based computer. These systems are designed for workshop use and are prohibitively expensive for the DIY mechanic to buy, costing more than most older cars are worth. Visiting the dealer will cost at least 1 hours work for one read of the diagnostic trouble codes, not economical for an intermittent fault requiring several or many reads over an extended period of time and not practical for a car that doesn't even start or drive.
OBD2 and ELM327
Limited engine diagnostic code reading can be performed by an ODB2 reader on all Petrol models. Only Diesel models after around 2005 are OBD2 compatible, pre 2005 will require Lexia. These limited tools allow the reading and erasing of some fault codes stored by the car during error conditions detected by the various computers in the C3. The code and description given by these generic OBD2, often ELM327 based, can be useful for the most basic engine faults. Some of the very specific fault codes may not be read or interpreted by the generic OBD2 scanner giving a misleading picture of the fault conditions present on the car.
OBD2 or ELM327 won't read all the ECUs in the Citroen C3, so consider the lexia/diagbox if you have BSI or any faults that are not engine problems.
A basic stand alone OBD2 code reader is the MS309 from Amazon, but you can also find very similar OBD2 readers on ebay too, for not much money It is not lexia and will only do a small part of what lexia can do but can read most engine codes. A basic OBD reader may be all that is needed or just a first step for engine diagnosis. A later upgrade to lexia/diagbox is still possible if deemed necessary to dig deeper.
If you want to use your iphone or android device you will need a OBD to bluetooth adaptor and some software from iTunes or your app store. A suitable OBD2 BT adaptor for android is available here.
Some iPhones have issues with bluetooth, so its worth reading the reviews for reports of iPhone connectivity for any particular bluetooth device.
The software or app which is needed to display the fault information can be downloaded from iTunes or from the Google Play Store.
A popular app for android OBD2 diagnostics is 'Torque' by Ian Hawkins, there is a free version available for android Here and the extra features can be unlocked later.
Early model Diesel C3s do not conform to OBD2 (up to around 2005) so all the ELM327 and generic OBD2 scanners just don't work. If you have a pre 2005 Diesel C3 or wanting a much greater range of diagnostics, beyond just the engine functions, with a PC based interface you can use Lexia. Finding a China made 'clone' of the dealer tool, called 'lexia 3' or 'diagbox' is the solution. Early cars (2002-2006ish) will be happy to communicate with older version of the software which must be run on a Windows XP system. An old laptop running XP with at least one USB 2 port will normally suffice.
You can look for lexia 3 here, on Amazon.co.uk.
A typical Lexia tool with it's leads and the extra parts often found the box:
Later model cars (post 2009) or Laptops/PCs running Windows 7 will need a later version of the hardware and software, an updated version called 'diagbox'. This is a China clone of the later diagnostic tool and can be found in this link, on ebay
If you don't mind waiting, a month isn't uncommon wait for a lexia tool as an import from China (the country of manufacture), then have a look on ali express (here) for lexia. There is an opportunity to save money on the purchase at the expense of a speedy delivery.
Here are some tips from the forum on getting lexia installed and I will add more here as they become known.
Citroen C3 1.4 16v HDi white smokeAdam wrote:(TIP. If your laptop has an SATA interface for the HDD and your installing windows XP, be sure to turn off "SATA Native Mode" in the BIOS as the XP install will not see your new shiny HDD, it took a few hours of irritation till the penny dropped.)
Lexia 3 & Compression test and P1197 solvedRC3D wrote:“The communication card is incorrectly initialised, The tool must be restarted” - You need to accept the error by pressing the Return button on the keyboard and then disconnect and reconnect the USB lead (the OBD2 lead) to the computer.
If you are seeking assistance with error codes on the forum, use lexia and list the error code ('Pxxxx' code), its description as provided by lexia and the symptoms the car is suffering from. If any previous work was carried out just before the fault and after the fault, this should be included too.Arfur Dent wrote:If you are presented with a long list of codes on the first time the Lexia is connected to the car, don't panic. Delete all the codes that can be deleted and start and run the car, or try to start the car again. Only the relevant codes will be kept or stored again, so a second reading will hopefully give you a more concise and relevant list of error codes to work from.
If you are prompted to enter the C3s RPO number, then you can easily find the RPO from This topic RPO Birthday for the Citroen C3.
To save a bit of typing and to give a fuller picture of your error codes, system readings or settings, a screen capture of lexia can convey much more information. To capture an image of the current screen showing, try this tip by C3CAR.
C3CAR wrote:A quick way is to just screen grab with ALT and PRT SC (or ALT and PRT SCR) and then open paint and paste into a new image. Save the image as a jpg and then attach it to your post