Canbus compatability, loom splicing.

[Haz]

On a side note to the van project, I've not experimented much with splicing looms on cars with canbus links and the likes so seeking advice, albeit probably to complex for me to understand!
I realise some components need to match, well most really. But when most differs and can't be used what are the options?
I figured the best way to start was to have similar year and spec.
2005 trafic full engine loom, aux loom, fuse box. Dash loom, fuse board and aux switches - ac, elec pack etc. Key, transponder, body module and ecu. It's a later loom than mine with a connector for the rear loom as the earlier ones were one peice so just that to add in.
2005 megane full engine loom, part aux loom, fuse board. Dash loom inc body module, key card and receiver, stop/start, instrument cluster and complete column.
Most mechanical items won't transfer so I'm hoping it's electrically possible or at least know for sure if it definitely won't work before putting many hours into it!
I've opened the looms up and at a glance the theory works with the traditional renault colour scheme keeping the basics simple.
Thoughts are - megane engine loom with all the aux bits removed. Lives, sw live, earths and relays adjusted and fitted to correct ones in the van fusbox. Minimal Megane dash loom comprising stop/start, transponder, card reader and card, instrument cluster and body module both with excess relevant loom removed.
All megane lives, sw live, earth and relays adjusted into the van dash loom and fuseboard. Steering lock and barrel removed, wiring adjusted to suit megane. Some wires transferred from van instrument cluster and to meg body module, mainly stalks related.
That, in theory, should allow it to run, not considering all the pedal switches, doors closed etc but that's the last of the problems.
The last component to be removed from the van loom is the body module. My assumption is that half the wiring will be disconnected when fitting the megane unit, thus the remaining should correspond with what is removed from the megane dash loom back to singular wires ie central locking, windows, ac. using the full van canbus just controlled by the meg unit.
As they're just switches I'm assuming they just trigger the body module and it should respond the same albeit throw some codes up?

Any input from experience?
Thanks

 

[DaveL485]

Absolutely no idea other than to say when I interrogate the engine management on my Meglio now I put it in as the Megane, not the Clio.

 

[Brigsy]

In for comments as i have a similar project coming up, you may need the steering lock for the meg loom, i might be wrong but im sure it completes the immob setup.

As long as the immobiliser setup is complete, the two looms combined should work in theory, may have a few errors a bit like when using a standalone ecu tied into a canbus loom. From previous experience on my Kangoo conversion, the uch/bsi just switches things on and off, nothing fancy, i.e. Airbags providing resistance is met or coded out, no faults will trigger. The switches are nothing fancy, so providing what is wired matches the original, it should work ok.

The other option, and poss easier could be fit the full megane loom inc clocks, rewire the van rear light harness into it, and the abs will prob work OK if the amount of teeth to trigger are the same on the van as meg.

Bit of a wild card, but if the ecu’s are very similar, it may be possible to transfer immobiliser data over and get the meg ecu on the van loom? One for Scoff, he would have an idea if its do able or not.

 

[DaveL485]

One for Scoff, he would have an idea if its do able or not.

I think that depends on the chip inside the ECU, but I know you defo can on this type/shape of ECU

 

[Haz]

Yeah it thinks it is which ever ecu set up is fitted.
I have the column which has the immobiliser transponder/Steering lock.
I've yet to update the van thread. My conversion should be straightforward as it's the same, just a more tuned engine - a bigger turbo and injectors so should just be a case of swapping a couple of sensors and coding injectors to the van ecu, additional sensors for the meg/laguna are just left unplugged as the van doesn't use them. It should run the 90bhp map if it allows the injector codes, mapping will hopefully see an increase back to the 130bhp and up to maybe 160/170?
But that's what has raised the question, and I've had chance to look over the loom. The extras on the engine allows cruise control amongst other things, not that I'm intending to use it, just theory.
The clio/meg/laguna are all stop/start, key card etc and the same platform so operate the same way. So although it may have a differnt door lock, mirror etc it should work or at worst recode the ecu to suit if thats possible.
Likewise the van is more like the 172 setup. I'm presuming if I fitted an early f4r setup the clio body module will talk to the van sensors. I was hoping the other recent van conversion thread would have revealed a bit more but nothing.
My thoughts are that version one clio won't talk to version two body bits? Like fitting the 172 setup into a mk3.
The engine will run. If I add and wire up the column, cluster etc that would match up and I could utilise cruise control but if it doesn't recognise the door lock it, and it can't be coded then I assume it will throw a code up and it simply can't be used.
Scoff says he's limited to clio/meg regards he has only only looked into what's required for mapping so just males sure everything matches, if you can get it to run he can map it.

 

[Haz]

The laguna, meg and new van ecu are all like that, my original van ecu is the same shape but flat casing, no heatsink looking bit. Also where those have 2 blue smaller connectors and one big brown my original has one small blue and 2 larger brown.
Anyone have a 172 or the likes as a comparison?
All of the above seems possible, splicing non canbus wiring isn't an issue, I guess the question and what I will test should have been . .
Say it's all a meg can you change the window regs, mirrors, lock for others?

 

[Haz]

I think I may have been a little naive! I was looking through the bundle of bits I have and noticed that most that talk with the body module have codes on so it's as simple as recoding each component in it. It either has it in it's library and works as it should, or it doesn't and may work but will put a code up?
When doing the meglio's I guess the ecu sockets and body module are different, hence the loom swap?
Are the instrument clusters swapped? Same numbers?
Same numbers on the air bag modules?

 

[DaveL485]

When doing the meglio's I guess the ecu sockets and body module are different, hence the loom swap?

No, the ECU and pin patterns are the same, but you do use the Meg ECU, the Meg engine loom (which takes up 2 of the 3 ECU sockets) and the third ECU socket the 197 body loom plugs straight in to it. You retain the Clio instruments etc and it all works.

You do have to cut and shut the engine loom > UPC (Body control module), three plugs that control stuff like fans, starter, fuel pump etc, it's about 20 wires total, you can see that in my Meglio thread.