Lexia and OBD diagnostics

TL;DR
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.

Apps
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.


Lexia
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.


Tips
Here are some tips from the forum on getting lexia installed and I will add more here as they become known.

Adam 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.)

Citroen C3 1.4 16v HDi white smoke

RC3D 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.

Lexia 3 & Compression test and P1197 solved

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 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.

RPO
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.


Screen Capture
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

Fhew you are a clever geezer Arfur. As my previous Astra lasted sixteen years with no probs on engine management or auto gearbox ECU i hope and pray for the same.

Its ironic, all this nonsense around sorting electronic problems, the very system that is meant to keep your car running. As C3 users say there is nowt wrong with the car its just the electrics,

A quick video demo of some of the steps taken with lexia 3 (here) to find and diagnose faults on an early (pre 2006) Citroen C3.


Some faults have a fault finding flow chart included which guide you through further tests to complete, so you get much more than just a cryptic error code to work with.

A 2003 1.4 petrol C3 came by with the MIL and running in limp mode as documented in the Citroen C3 1.4 MIL limp mode shows P1161 TPS Copy fault topic.

Connection to an old version of lexia shows up a question mark (?) on the Injection (engine ECU). With the correct VIN and RPO a list is shown of the various ECUs fitted and when the choice is made warnings are given by lexia.

This suggests that the Lexia application needs an update to recognise the engine ECU fitted.

Actual ECU is an S2PM-380
Updating the old lexia that had version 3.45 to a later version of 5.02 by installing Diagbox makes the automatic detection of the ECU work correctly. This update allows further investigation of the fault with a level of confidence in the system and no warnings about things not being correct.

I found this while looking for information about running Lexia/Diagbox on a 64 bit Windows 7 machine. Lexia and Diagbox only support 32 bit versions of windows, but it is possible to install 32 bit Windows XP on a Windows 7 64 bit machine without dual booting, but rather as a virtual operating system. Windows 7 Professional, Enterprise, or Ultimate support XP virtualization.

Windows 7 64 bit running in XP mode to support Lexia

https://blog.aobd2shop.com/solution-lexia-3-v47-on-windows-7-64-bit/
https://web.archive.org/web/20141211053 ... -7-64-bit/

https://web.archive.org/web/20141211053715/http://blog.aobd2shop.com/solution-lexia-3-v47-on-windows-7-64-bit/ wrote: (Solution) Lexia 3 V47 on Windows 7 64-bit
Posted on 2014/06/11 by 管理员

Recently I have got myself the Lexia 3/ PP2000 cable to play with. The obd2 tool is normally installed on Windows XP PC. But as it turned out, with little manual tweaking it is possible, contrary to the popular belief, to get it working under Windows 7 64-bit.

So, I decided to share the instructions, hoping this will save someone a headache of dealing with dual boot and virtual machines with Windows XP.

The solution to the problem not as difficult as most people think. If you have install the driver and software on Windows 7 64 bit, you must uninstall the USB drivers and software first and then install and use Windows XP Mode in Windows 7. About how to run XP Mode in Win 7 PC, please refer to the link below:

https://windows.microsoft.com/en-us/win ... -windows-7

I have run Windows XP mode and it works good for my Lexia 3 V47. Tested and worked OK on my 08 Citroen C4.

Thank you to the 管理员 of https://web.archive.org/web/20190523121 ... 2shop.com/ for sharing the solution

Lexia does indeed run on a virtual PC, however if you are intending to do this, it's worth mentioning that Windows XP in virtual mode is just as vulnerable as machines running the now unsupported Windows XP. Also any anti-virus software that runs in the machines native mode won't be running in virtual mode, if you want anti-virus you need to install it again on the virtual PC.

I run Lexia in XP Virtual mode and to get round any vulnerabilities I disconnect from my network before starting the Virtual PC. You need to open resources on the host PC for the USB connection to work. I've not had any problems using this method so far.

hi all just a MaxiScan® MS309 CAN OBDII Code Reader but can`t plug it into the obd port can`t get it to fit ??,have i got the wrong one.

Hi philtop.

Some older C3s aren't OBDII compliant, Peugoet/Citroen used their own proprietary system called VAN rather than the now industry standard CAN.

The socket looks similar to an OBDII connection but it isn't, post facelift is however compliant and will to some extent work with generic readers.

This is the reason for using LEXIA, it was made specifically for older Peugeot/Citroen vehicles.

Perhaps worth mentioning, if you're running LEXIA software in a Virtual Machine as part of Windows 7 Professional and are thinking about upgrading to Windows 10, you will loose Virtual Machine.

Contrary to what Microsoft would have everyone believe, Windows XP is still supported. Unfortunately not for much longer though. Windows XP is still used in lots of commercial embedded applications like cash machines. To give industry time to update they have paid to continue the update service. There is a way to make any copy of Windows appear to the update system like an embedded version by editing one flag in the registry.