PSA Service (SEDRE) wiring diagrams

[MikeT]

Trying to use them in earnest is a frustrating process for me (no surprise there, I hear you say! ).

I can find zero reference to wire colours. I know from solving my Xantia cooling fan issues that wire numbers (printed in dot-matrix micro numerals along the wire length) is the preferred method. As the wires come pre-pigmented, is there not a pin-colour reference for these hidden somewhere? I can't find them.

Also, I'm struggling to find voltages associated with pin-outs. I believe I spotted one once, but whenever I'm actively seeking a voltage, they're nowhere to be seen. Obviously, the majority will be straight battery voltage and earth so perhaps basic (experienced) deduction is all that's needed?

But I just want to end on another issue I've just noticed regarding component connector labelling.

Case in point is max1 ECU reference voltage issue (see his thread for more detail) where I wanted to familiarise myself with the accelerator pedal position sensor and noticed these plug discrepancies in the various sections.

In the "principle" section it shows 6V MR (6-way, Brown).
In the "synopsis" section it shows 5V NR (5-way, Black)
In the "wiring" section it's 6V MR and
In locations it's 4V NR.

The wiring diagram max has says it's a 5-way.

I guess they're more of a guideline than factually correct?

[GiveMeABreak]

They can change between diagrams - even pulling the right diagram up for a specific model and specifying the correct options may still give you anywhere up to 3 different sets of diagrams. I don't think they account for all the variations of installed options, so you have to do a bit of investigating to work out which is the right one. It's also been known for the wires to be on different pin numbers too Mike.

[MikeT]

They can change between diagrams - even pulling the right diagram up for a specific model and specifying the correct options may still give you anywhere up to 3 different sets of diagrams. I don't think they account for all the variations of installed options, so you have to do a bit of investigating to work out which is the right one. It's also been known for the wires to be on different pin numbers too Mike.

I guessed right then, model variances and revisions.
Stands to reason there'll be pin numbering issues too if they quote 4, 5 and 6 way connectors for the same part.

Are wire colours revelant in any way marc or are they now considered largely redundant due to automated, proprietary diagnostics? Apart from connector colour codes, I can find no further information.

[GiveMeABreak]

The wires should be coded with the wiring code number - but sometimes there isn't enough room to see it before removing the sheathing or running out or room! I would guess therefore that colours are pretty true to form - I've found that mine match up so far.

On some models, the actual fuse boxes are found to be in a different location too! The Xsara and the C4 to name a few on some variations!

[MikeT]

The wires should be coded with the wiring code number - but sometimes there isn't enough room to see it before removing the sheathing or running out or room! I would guess therefore that colours are pretty true to form - I've found that mine match up so far.

On some models, the actual fuse boxes are found to be in a different location too! The Xsara and the C4 to name a few on some variations!

Yeah I get the numbering but you can see a wire colour at a glance. For instance, sorting out the ECU plugs to find the wire connected to pin 32 would have been a lot quicker if I knew it's wire colour.