2005 1.4 HDI SIEMENS to BOSCH ECU SWAP!!!!!!!!

Hi, finally relented and joined up to yet another forum after a lot of my citroen related questions seem to bring me here when on search engines!!!!
Know these C3's, C2's are very similar in design and parts as often swapping bits and pieces around to get cars on the road again. This latest issue i have is a 2005 C3 that donated its engine to my C2 and went together a treat. All worked and been faultless for a few thou miles!!!
So had a "scrap" C3 sat there less an engine and a knackered box that i thought scrap, break or fix........
I went with fix as i always do hence a long list of cars in past ownership (250+) and currently (around 20).
Fortunately its just a hobby so a lot of work for very little reward is the way i go!!!! I've been looking around on salvage auctions and the like and came across my donor with 78k on '07 with door, sill and wing damage.
Now this was my 1st mistake. I've been led to believe Bosch systems feature on mk 1 models and '05+ use Siemens. On delivery i then discovered its a Bosch set up .
Pulled lump out all the same and checked engine loom plugs and same amount on Siemens one from scrap C2 engine. Chuffed to bits i was so carried on and got it all refitted into the 1st C3. I plugged enough in to start it up. I swapped all bsi, bsm,clocks,ecu and used key innards from donor. (found out the keys are internally different, one mounts battery on board, other on case. Also the spring mech looks different between them too).
Hmmm, nothing happened.
So i ran a wire from solenoid to battery and fired up and purred like a kitten with no smoke or warning lights!!!!
I decided it was 90% at this point and carried on refitting front end, shafts, a leg as spring was snapped, g/box oil and the water. All good, took for a drive, 14 miles without fault. Took to a garage and had him look quickly at a plug that i hadnt plugged together as it was different shape. He couldnt confirm what they did from autodata.
I'd probed them out on original loom and found there was 2 of any use. Reverse lights and water in diesel. I'd also unplugged on C2 and it didnt affect starting or running so i knew it wasnt too important.
Ive searched them out on Bosch engine loom and found an extra wire that i cant find a home for but the other 2 were there. Ive temp connected the 2 i know. This plug is the little one next to the battery against the bsm fuse board.
Thank you if your still reading!!!! So i'm now looking at next steps over christmas with it.
Step 1] Run a wire to ignition barrel.
Step 2] Redo engine fan relay so it doesnt run in default mode (refitted original as plugs different) or put to a switch in car.
Step 3] No reversing lights.
Step 4] No e/mirrors.
Step 5] Replace other half of engine loom (which i've already completely removed from donor).
Step 6] If i change that half will i need to change the little bit of dash loom and then the other half that does to the rear as well.

Hopefully some of you more electrically minded guys may have some good advise that can enable me to complete it. I'm not keen on bodging wiring looms so would rather replace then start butchering bits into it.
Can anyone confirm what main looms are used in the building of them as i'm hoping there is some of it thats the same on any model regardless of spec and fuel etc.
Ive stripped a few C2's and swapped over looms after corrosion repairs and previous bodges in past so i know whats involved if i have too.
Awaiting some correspondence from some of you fellow Citroen enthusiasts who might have the info i need.

Siemens car CW55 ABN
Bosch car KU07 ASO
Has anyone tried this and succeeded or is it just me, cheers and a merry Christmas Chris,

Renault9turbo+ wrote: ↑Sat Dec 22, 2018 6:40 pm
Siemens car CW55 ABN
Bosch car KU07 ASO
Has anyone tried this and succeeded or is it just me, cheers and a merry Christmas Chris,

Hi Renault9turbo

I see you have a pre 2006 and a post 2006. This is probably the worst thing to do. Either stick with all pre 2006 or go all post 2006 up to 2009.

There were some changes on that 2006 period for VAN and CAN bus so you have the most potential problems.


I would like to know if both the ECUs come out of BOSCH injection systems (found in 8v engines) as opposed to any out of a 16v engine with the DELPHI injection system.

A photo of the sticker to identify the BOSCH ECU

and one of the SIEMENS ECU sticker to show 'SID 801' etc please

Hi, thanks for a quick if slightly worrying reply. The 55 plate is registered 5/11/2005. Its identical to the newer one, identifiable from the revised dash, clocks and radio etc. So I like to think it actually is unless your gonna share something bad with me....
These are both 1.4 8v 68bhp models. Running different ecu's as described earlier but obvs not the twin cam model ecu and software.
I'll post ecu pics later but now off to bed after my shift!!
Thank you.

The bosch injectors are on the bosch ecu'd engine. There are Siemens injectors in the Siemens engine.

Looks like you just made it with a very early 2006 model made in 2005, phew.

I really need pictures of the stickers on the ECUs to get the part numbers before I can do anything useful.

I have never swapped systems or know of any system swaps between Bosch and Siemens, but you are along the right lines by staying away from the Delphi fitted to the early 16v models.

Merry Christmas

That's a relief I have got half the battle right!!! Hopefully there is some pictures uploaded now.

The plug is one from engine loom that comes through bulkhead and does brakes etc and all front end wiring. The white plug goes to dash somewhere. Why is there an extra wire in it?? I don't want to change this piece of loom over if I then have to take dash out and swap the last bit over because of the wire in that plug actually doing something useful.

Whilst looking to get the C2 back on the road I did think about one of the 16v engines as they are a fair bit more powerful but I accepted it would need a complete loom change to stand any chance of working with the Delphi system so I decided against it. But I have got the intercooler and pipes from one to fit too the C2 to replace the 1.6 hdi intercooler it's got at the moment as I couldn't find the C3 one anywhere at a decent price. (The C3 one has different angled holes for the pipes to fit onto which clear turbo a bit better) . I didn't notice much difference but on the rollers it did as graph shows. After mapping it was transformed and made 94.6BHP.

Hope Everyone enjoyed Christmas and New Years (shortly)!!
Set myself a goal after xmas of having it sorted by end of year........
I got the loom from the donor car and spent 3hrs stripping loom out of road car Saturday. Had to get the bumper off and lights to assist in accessing the loom to washer pump and abs etc. Been at it again today from 10ish till 3 and had siemens loom out and bosch one back in with just bsi to connect up, loom around battery and bumpers/lights etc.
Had a bite to eat, carried on till 6:30 with all back together by then, just glovebox to refit and scuttle trim which i removed to get to the plug and earth on wipers.
Changed engine fan to the bosch one as plugs didnt match and tried off key and went engine fired 1st turn!!!!! So starts off key, fan doesnt run all the time!!!!!
Still no reverse light or e/mirrors working atm. Seems fuse maybe........