hypest

Hello forum,
I've recently bought an OBD2 tool to experiment with statistics on my Citroen C4 (2007 model), but it seems that at least one of the OBD2 standard PIDs are not supported! I'm referring to the Fuel level related PIDs. PIDs 0x0A and 0x2F are not supported by the C4.

So, my question is, does anybody know how can I retrieve these readings? In general, does anyone know the Citroen-specific PIDs, modes, or CANbus messages?

thank you!

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techbod

not an easy answer for this because it will be CAN related so depends on the diagnostic tool your using and the software ELM327 or similar with USB and Vehicle explorer software will interrogate the complete system ( I got a full working copy off eBay ) unfortunately it doesn't work on the older Citroen's but should be good for the C4 2007.

edit:
the software I bought
http://cgi.ebay.co.uk/OBD-DIAGNOSTIC...d=p3286.c0.m14

lexia 3 is what the dealer uses but you could look for the software and it should work with ELM 327
http://shop.ebay.co.uk/?_from=R40&_t...ugeot+Lexia+3+
this stuff is expensive

hypest

Thanx techbod!
I myself have a bluetooth ELM327 tool. My aim is to collect data using my mobile phone (WM6).

I will probably try the software you suggest. So, does it accesses the "hidden PIDs/modes" and CAN messages? (is http://www.obd-2.com/ the Vehicle Explorer you're referring to? If yes, I don't see it mentioning working with ELM327).

I had in mind to "somehow" find Lexia (too expensive indeed for my hobby-related projects), to study it and perhaps discover the special messages it uses to access the measurements.

Your post gives me hope . I was afraid that an ELM327 tool won't be sufficient on its own...

techbod

never tried the blue tooth device im told its good on the newer cars, obd2 yes that's the one and elm327 works with it I have used it good thing with that program is it scans for any pids available and gives you a full report as to what you can view ( you can force pids if you know them ) elm327 is a powerful little tool and multi protocol only the software is what controls it so if you have poor software then you get poor results, I might consider the blue tooth option one day.

quick edit: elm327 is an interface to your cars computer(s) and its the most up to date but if your software isn't up to the task then it will fail also you need to do lots or research on this subject so you can control the interface via the appropriate software, most newer diagnostic tools are based on elm standard even the lexia3

hypest

I tried the Vehicle Explorer earlier today, but without success
I could get it to access the port but no traffic is visible (the elm327 has some LEDs that blink when accessed). Perhaps I'm doing something wrong in the "Gateway" settings...

Anyway, if what Vehicle Explorer does is just to scan all PIDs (00-FF) in OBD2 mode 1, then I can do it also in my own program, which is simply a serial port client. The ELM327's interface is just plain ASCII serial: to retrieve PID 0x2f for example, you send "012f" and you receive the answer...

techbod, please, can you post the "Gateway" settings you use?

Also, have you tried Lexia3 yourself? does it need any "special" hardware/cables besides an OBD2 tool? For example, the Lexia3 manual, mentions a "Citroen Communication Interface" cable; is that necessary?

thank you very much

techbod

in the protocol you have to turn the CAN on then select your comms port ( although it says blue route ) but not sure if blue tooth will work with it but if you got that software then you should also have Citroen software on it ( I'm still working on that one ),
I have used lexia3 and it is impressive but the cost is out I also only do it as my hobby since I retired, lexia3 is software orientated so the 16 pin should work ok because its the interface that does the communications and lexia3 is USB so not sure blue tooth would work with the hardware.

lexia3 is 2 components (hardware & software ) the software is the main thing, many interfaces will work with the software as long as its CAN related as yours is so your bluetooth should work with it setting up the software to the laptop and the interface is the key.

edit: and well worth a read
http://en.wikipedia.org/wiki/Controller_Area_Network

http://www.interfacebus.com/Design_Connector_CAN.html

http://www.bridgwater-electronics.co...CAN+Bus%3F.php

hypest

Some notes:

1. ELM327 reports that the protocol found in my 2007 Citroen C4 is KWP-fast (ISO-14230-4). So, is it possible your Xantia uses Canbus but the C4 uses KWP?

2. The ELM327 serial protocol is ASCII based: to send one hex byte, you actualy send 2 ASCII bytes, one for each nibble you want to send. Example: to send the binary 0x3F, you send one "3" (ASCII code 51) and one "F" (ASCII code 70). So I wonder, does Vehicle Explorer respect/knows that, or does is send the bytes as "normal" binary bytes? What I will try next, is to monitor what does Vehicle Explorer send to the serial port (using a serial port sniffer). I suspect that Vehicle Explorer tries to talk directly on car bus via rs232. So it puzzles me that you report that you have used it and worked

techbod

you need to go to options and turn on CAN otherwise it doesn't see anything apart from engine management.

edit: my xantia is ISO 9141 not CAN I think the KWP ( normally used in FORD )but not saying it isn't used the later ones with CAN bus integrated, as of 2008 all the cars will be CAN bus only

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