S1 V6'ers, tell me then...

[citroenxm]

.... what is this Back Box hidden behind the drivers wing with sealed wires connection going to it???





I have rescued it and the COMPLETE full harness right from the massive connector in the scuttle to the fuse box etc...

Just wondered what it was.. Ive taken a fair few Xantias apart, S2's aswell, but NEVER seen it before..

[citroenxm]

Thats a f kin big relay lol... the cruise ecu is under the drivers seat.. its a vac type system like the xm.. but ive never seen this on an xm..

[VertVega]

I had the same box in mine (2.0 16V '98 MK2) which was hidden in driver's side, front wheel arch
There are 3-4 relays in it, water proof tight sealed case, holding together with screws (T20).

The infamous headlight washer relay (big ORANGE color) can be found in there. I don't know about the other relays.

[citroenxm]

Thats strange because my series two exclusive headlight washer relay (big orange one) is under the bonnet in the fuse box next to the main supply fuses..

Ive not looked at my xantia s2 exclusive to see if its there or not..

[VertVega]

That was also a mystery for me when I "discovered" it there but other MK2 owners didn't know anything about such a box. Not all MK2 models had it. This I know from some scrap cars which I have seen and they had the orange relay in the fuse box under the bonnet

Edit: I checked from my old pics. There are 3 relays,
Big orange, small gray, and small purple color cases.

[KP]

How did you undo the big connector in the scuttle going into the fuse box?!

[addo]

There are one or two deeply buried T20 machine screws holding it in. You need a Torx driver of the type that is a long-ish "L" shape to access the head.

RE the relay box, it seems from my observation they kept the S1 harness or a large portion of it, for the V6 facelifts possibly up to 2000 or so.

[citroenxm]

How did you undo the big connector in the scuttle going into the fuse box?!

Show you later unless your v6 shell has gone. Simple once you know how..m

[Mandrake]

In my early S2 V6 there were three relays in that box, although I think there are spaces for up to 5 in the plastic moulding. One was the cruise control relay, one operates the park lock solenoid for the gear lever and the third is also gearbox related (its shown on the gearbox wiring diagram) although I haven't worked out quite what its purpose is.

[VertVega]

and this was from mine, a 2.0i 16V '98, MK2.
It seems that there are different configurations. I hope this would help someone in future

Edit: It was a LHD car and this box was on the left side of the car.

[taffy]

im pretty sure one of theses is the imobiliser relay...im hearing a click from this area at the mo as my imobiliser playing up on s2 hdi 110...i winder if this can be bypassed?

[Mandrake]

There's no immobiliser relay taffy, that would be far too easy to defeat.

On a V6 the immobiliser feature is built into the engine ECU where it will refuse to pulse the ignition coils and injectors until it has received the unlock code from the CPH - no relays involved and no easy way to defeat it.

On an HDi I'm guessing it uses the armoured pump approach where the immobiliser code is sent to the chip inside the pump so short of de-armouring the pump it can't be defeated either...

[citroenxm]

No, immobilisation on a HDi is all in the ECU.... Theres nothing extra on the fuel pump or anything.

If you want to unlock a HDi, you need to send the ECU away to have the software modified and immboiliser feature removed..

[taffy]

somekind of relay that ive never heard before is clicking either where theses relays are or poss under the ecu...i put key in and turn it to prestart and a relay clicks and then clicks again and the imobiliser light starts flashing and beeping...its not fuel relay or ecu as have held them as the click occours....is there anything under the ecu box perhaps?

[Mandrake]

No, immobilisation on a HDi is all in the ECU.... Theres nothing extra on the fuel pump or anything.

If you want to unlock a HDi, you need to send the ECU away to have the software modified and immboiliser feature removed..

Ok, it works the same as on a petrol then - no relays to defeat then I'm afraid taffy...

Is your immobiliser intermittently refusing to unlock ? (Flashing yellow light and audible warning when turning on the key)

Mine occasionally does the same but because (as I've discovered) my engine ECU is unlocked, it doesn't prevent the car starting.

I've tried a loaner pair of engine ECU and CPH in my car for other reasons, an engine ECU which is NOT unlocked, and the immobiliser has failed on me once. From this I conclude the problem must be in the transponder antenna on the lock, the wiring or the transponder chip in my key.