citroen loom wire numbers

[nick9one1]

Hi all! Im a UK 205 owner with a few questions about citroen wiring.
I recently bought what I believe is a XU10J4R to replace the 1.9 in my 205.


I dont know which Citroen it is from but I believe either the Xsara or XM.
I have got to the point where the engine is in the car, everything attached apart from the wiring. I have read plenty of guides about how to mate the 205 loom and other looms together as long as you can work which wire is which. The 205 loom is cut labeled and all ready to be joined but I cannot work out the wires on the citroen loom. I htought the wires might be coded the same as the 306 loom, which also uses the XU10JR4 but im not that lucky!

so if anyone can tell me for sure how I can find out what car the engine is from, or point me in the direction of wiring diagrams I would be very greatful!

a couple of pictures of the citroen loom

and here is a nearly complete list of the wires at the 2 plugs I need

wire codes from the ecu side multi plug from the citroen loom. 18 wires

122A White
122B White
BB8 Thick blue
426 Green
1234 Green
822 Green
1223 Green joins from 1220 Red and 1227 White
CC2B Grey joins from CC2L Blue and CC2K Grey
120 Thick White
1212 Green
8055 White
141 White
820 Red
821 White
1360 Green
1232 Red
140 Red
B14A Thick yellow

The other smaller part of the loom i have has all the plugs for water temp, alternator etc 14 wires in total
*B1*808 white
*31*808
*G4*C02?
*G4*8081 white
*E9*415
*B0*405 red
*B0*401
*E9*1070 green
*F1*1010 thick green

many thanks!

[CitroJim]

I've had a look in my Xantia wiring diagrams for the XU10J4R and there are several very different variations, depending on ECU used. In none of them can I tie up your wire numbers.

I can scan and post the wiring diagrams I have as they may assist you but in order not to confuse further, it would help to know the ECU you have/plan to use. It would also help enormously to know what year car(roughly) the engine came from and the engine code. I suspect it's an RFV.

You may have to do a reverse trace by identifying the wires from the engine sensors and tracing them back to pins on the ECU plug and working out the wires that way. Again, I can post up diagrams to help.

Note that the ECU that would originally have been with this engine is not likely to be usable unless you have the keypad immobiliser and code or RFID transponder to go with it. Without these it's not straightforward to unlock the ECU.

You'll not be able to use the original 1.9GTi (Bosch L-Jet) ECU with this engine.

Why are you wanting to use this engine particularly in a 205GTi? The old XU9JA is a lovely engine...

[nick9one1]

fantastic, thanks citrojim.

well the 1.9 I had needed a lot of work and I picked up this engine cheap so I thought I'd attempt the conversion. The ecu is unlocked so hopefully I wont have any problems with keypads etc.

right.. the guy I bought the engine from had no idea on the car, but I can tell you the ecu type (see attched pic)

where do I find the engine number? I had a look around the oil filter where I thought it was but cant see it?

I have also found a pinout diagram for a gti-6 ecu, but not sure if it is the same.

The only worry I have is that there is some of the loom missing? the smaller loom in my picture (red background) is completely separate from the ecu.

any diagrams/pics would be a great help, thanks!

[addo]

Looks like a late Xantia I ECU, by the 96-prefixed part number. Also Xantias (and presumably others) do have a separate small harness for the injectors and engine sensors.

While the plugs may look similar to each other, you'll find there's only one position each actually fits in. This will help you ID the sender wires - that coding is printed along their length.

[CitroJim]

Excellent. Knowing the ECU is a great help

The middle picture is your double injection relay. Item 1304 in the circuits below in the next post.

Stand by whilst I go and look at my diagrams.....

[CitroJim]

Here is a link to the general MP51.1 injection circuitry around an XU10J4 engine. This was taken from the Xantia 1.8i and 2.0i 16V diagrams for the 1996 model year. Addo, nailing it down to '96 helped enormously

XU10J4 MP5.1.1 Circuit

To help identify the individual bits on the circuit diagram, look at the four digit code next to it (e.g. 1320 for the ECU) and look them up on the two following tables:

Codes Page 1

Codes Page 2


NB. Those diagrams are the ones applicable to XU10J4 engines without ACAV. If yours has ACAV (Switchable inlet manifold passages), I have the circuit applicable to those as well.

Hope that helps...

Good luck with the job and let us know how it goes...

EDIT: Here's a drawing of the engine loom

[nick9one1]

great! thanks citrojim you've been a great help! now i just need to figure out the diagrams! im not sure if at has ACAV, how can i tell?

[CitroJim]

Looking at your engine picture Nick, I don't think yours has ACAV. You can tell by the presence of two vacuum capsules on the inlet manifold that operate butterflies inside to change the manifold geometry. It's to help optimise low-speed torque and high-speed power; normally mutually exclusive things on that sort of manifold.

If you need any help interpreting the diagrams, just shout...

[nick9one1]

well after spending a while pondering over the diagrams I think I do need some help!

I basically need to know from the citro multi-plug which wires I need to splice into the 205 loom,

I believe this is roughly right from the 205 brown plugs:

9 Pin Brown connector

1. Reverse light (wire 52, brown)
2. Reverse light (wire 53, purple)
3. Coolant light (wire 47, yellow)
4. Coolant meter (wire 47a, red)
5. Alternator (wire 7a, brown thin wire)
6. Oil pressure meter (wire 30, lilac)
7. Oil temp meter (wire 30a, white)
8. Oil pressure light (wire 30b, grey)
9. Switched positive (wire 2, light blue)

6 Pin Brown connector

• Earth (green & yellow)
• Rev counter wire (112B).
• The thin red wire (74a) comes out the other side of the plug as wire 32a.
• Thick red wire goes in as 2 & out as 2a to the coil

[CitroJim]

I've scanned the 205GTi Engine Management Diagram here Nick but I guess you already have this diagram.

It's not so simple as just splicing the new engine loom into the old 205 loom. Basically, provided all the sensors are wired to the ECU, all you need to do is provide switched and unswitched 12V feeds to the relevant double injection relay pins and anywhere else on the ECU where a feed is required.

Note that you cannot use the existing tachymetric relay in the 205 for continued protection in case of an accident (it stops the pump if the engine dies) and you really need an inertia switch to do the same in case of a bad bump. It's very dangerous to not have this protection as a pump that continues to run in the event of a crash... You know the rest!

All you need to do to work out where the 12v feeds are needed on the MP5.1 ECU is to follow the feeds down from the battery, ignition switch and fuse boxes.

I'd leave all the existing 205 wiring as-is and just disconnect the old ECU and tachymetric relay. This way, if you ever want to revert back to a JA engine you can. Lay in all new wiring for the MP5.1 ECU and to save load on the ignition switch, use a relay for the 12V switched feeds to the new ECU. Do fuse them as they are in the Xantia.

Are you a member of the 205gtidrivers forum? It is/was an excellent place. I've not been there for a long while now as it brings back painful memories of my own long departed 205GTi

The remaining problem is the tacho as you'll be using the XU10J4 coils and these don't give the right signal. I seem to recall the lads on the 205gtidrivers forum had a solution for that.

Be sure to mount the new ECU in a protected place. I've seen some conversions where the ECU is located, unprotected, in the engine bay and that is not good. Best to locate it in the cabin in roughly the same spot as the old ECU. An unprotected ECU will so die in the heat and damp of an engine bay. In the Xantia they are in the engine bay but in a nice warm, dry box.

I well remember the aggro one of those brown connectors used to cause

[nick9one1]

thanks again! I do have the 205 diagram but its good to have a digital copy. yes I am a member of the 205gti forum but nobody on there seemed to have a wiring diagram for the xantia the 306 gti-6 and xsara vts are the popular ones to do as they are 167bhp, unfortunately the wiring looms are numbered up very differently! although the block and the majority of the engine is the same.

anyway with your help I have just about managed to complete my wire list!

so far..

122B White battery +ve control unit to engine management multi-function double relay
BB8 Thick blue battery +ve control unit to engine management multi-function double relay
B14A Thick yellow ecu to maxi fuse unit?
120 Thick White battery +ve control unit to engine management multi-function double relay
1360 Green vehicle speed sensor to instrument panel / ecu

1232 Red Canister bleed electrovalve
1223 Green Canister bleed electrovalve to throttle housing element / relay
122A White oxygen sensor (front)

1234 Green AC
8055 White AC
426 Green diag connector
141 White diag connector
142 green diag connector
140 Red diag connector

CC2B Grey
820 Red
821 White
822 green

the rest don't seem to be on the diagram?
(ive made it colourful so its easy to see the wires!


I think the loom i have still has the inertia switch? it looks like a block with a big rubber button on top that rattles?

once you have owned a 205 I don't think you ever forget the notorious brown multiplugs!

[nick9one1]

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