2.0 Auto diagnostic socket location

handyman · Post by **handyman** » 09 Jan 2008, 09:34

A friend has asked me to have a look at his 1995 Xantia 2.0 petrol Auto as the engine management light illuminates intermitently, without any deterimental effect to the performance of the car.

I have a two pin diagnostic reader and according to the Citroen wiring diagram, this car has the two pin diagnostic socket, but I am bu**ered if I can find it.

I have looked in all the obvious places, by the ECU, by the bulkhead, by the fuse boxes, internal and under bonnet.

The car has the earlier carbon filter system fitted and I remember reading earlier posts about this causing false readings, as there is a feedback loop to the ECU. However, it seems impossible to get the details out of the archive.

Can anybody shed a little light on the location of the diagnostic plug? Any possible obvious causes for the service light to illuminate on an 80K mile car, when everything seems to be working ok? I have done the obvious disconnection and cleaning on all the plug-in sensors for the ECU.

Handyman

Sturdybloke · Post by **Sturdybloke** » 09 Jan 2008, 13:20

According to the Autodata book as follows - All 1.6/1.8 & 2.0 petrol Xantia with engine codes BFZ, LFY, LFZ, RFT, RFU, RFV, RFX, RFY, RGX, UFY, UFZ & UKZ between 1993 and 2000 have the connector in the fusebox

And its good to have the forum back

Clogzz · Post by **Clogzz** » 09 Jan 2008, 13:32

There’s a piece of loom going into the ECU box with a 2-pin bridged socket at the end.

That’s for the original location, but if it’s been used since, it may be dangling outside, up the thick loom going into the ECU box.

handyman · Post by **handyman** » 09 Jan 2008, 14:04

Thanks for that chaps.

If it turns out that I can only use the analyzer through the multi-point socket in the internal fuse box, anybody got any experience using this meter through this socket?

Handyman

Post by **CitroJim** » 09 Jan 2008, 21:51

handyman wrote:Thanks for that chaps.

If it turns out that I can only use the analyzer through the multi-point socket in the internal fuse box, anybody got any experience using this meter through this socket?

Handyman

If the 2.0 Auto in question has an RFX engine (8V) then hope springs eternal as you can connect a test LED and switch to the diagnostic socket and read flash codes. This can also be done on some 2.0 16V engines too, It all depends on the management used.

Let me have full details of the engine and management and I'll see what I can dig out...

Mandrake · Post by **Mandrake** » 10 Jan 2008, 06:45

citrojim wrote:If the 2.0 Auto in question has an RFX engine (8V) then hope springs eternal as you can connect a test LED and switch to the diagnostic socket and read flash codes. This can also be done on some 2.0 16V engines too, It all depends on the management used.

Let me have full details of the engine and management and I'll see what I can dig out...

Hi Jim,

I have the RFX 8 valve 2.0i engine as well, so I'm REALLY keen on this information if you can find it

What details do you need ?

Regards,
Simon

Post by **CitroJim** » 10 Jan 2008, 07:47

Mandrake wrote:[I have the RFX 8 valve 2.0i engine as well, so I'm REALLY keen on this information if you can find it What details do you need ?

That's all I need Simon, just that you have the RFX engine.

I have the information at home. I've just come into work so this evening I'll dig it out for you.

DickieG · Post by **DickieG** » 10 Jan 2008, 18:05

The issue you have here is that two pin diagnostic code readers are simply a box with an LED and a switch that rely upon the ECU producing what's called 'Flashcodes', pulses of electric current that illminate the LED a number of times according the the fault recorded, you then compare the number of pulses with a prompt sheet to find the recorded fault.

I don't think that a 95 Xantia does this as it produces its fault codes by way of 'datastream' which gives far greater information and requires a more professional tool able to read this constant flow of information.

If you want to see whether a fault is recorded at all, note whether the 'K' light goes out immediately the engine is started. If a fault is recorded there will be a slight delay of a second or two. The fact that the light illuminated previously doesn't mean a fault will be recorded.

If you wish to have a go at using your LED reader, you'll need to work out what wire on the reader is positive and what one is negative. Connect the positive wire to pin C3, the negative to pin C2. Operate the switch for 2.5 - 5 seconds and you should get one long flash and two short ones on the LED. This is trouble code 12, the starting sequence then read off the following codes and compare with the list (I've got it if you need it) etc.

If your friend is near me (M25 J15/16) I have the necessary equipment for both versions.

Mandrake · Post by **Mandrake** » 11 Jan 2008, 06:22

citrojim wrote:
Mandrake wrote:[I have the RFX 8 valve 2.0i engine as well, so I'm REALLY keen on this information if you can find it What details do you need ?
That's all I need Simon, just that you have the RFX engine.

I have the information at home. I've just come into work so this evening I'll dig it out for you.

Thanks Jim,

I found a thread from last year when I was asking about an ECU diagnostic computer that confirms the engine type including a suffix:

http://www.frenchcarforum.co.uk/forum/v ... hlight=rfx

Regards,
Simon