Immobiliser related problem

[JeffBr]

I’ve had an intermittent problem that’s got worse to the point where I only get the van started once in a blue moon. It’s a 2001 2.5L diesel Transit based campervan in good condition (42000 miles) so worth the effort to get it properly fixed.
With the key in ignition position 2 the immobiliser light flashes continuously for 1 minute and then pulses with 23 (I think ECU ID mismatch). Turn to position 3 and the engine turns but will not start. On the odd occasion when the immobiliser light doesn’t flash in position 2, the engine starts immediately.
I have a new battery. Both keys have been read buy a key specialist with equipment. I have tried three different sender units (the unit that wraps around the ignition barrel). I’ve interchanged the ignition related relays and fuses with equivalents in the fuse box. So, something is duff and almost unusable in the ‘brains’ stopping the ignition working (ECU or something else).
I’ve just tried to use common sense so far but I’ve run out of easy options.
Here’s the rub. The camper is in France (Argentonnay, Deux-Sevres region) and I can’t drive it to the UK in its current state. I could have a go a fixing it myself if I had a set of known working kit (ECU, PATS module, Keys etc), or, does anyone know a Transit Guru in France, or, if someone near-ish me in the UK (Salisbury when I’m back home) can def fix this kind of problem I could potentially arrange to get it there.
Any ideas!

[MinorMatt]

2001 would normally be a mk6, but being a 2.5 I am going to say its a very late registered smiley?

Can you double check the immobiliser code? I would expect 32 from your description. Someone has "fiddled" before, because when immobilised it shouldn't turn over.

32 is nearly always a dodgy fuse/relay/positive supply issue. Although I have had 2 occasions now where the ECU failed (but that's not intermittent).

So have you looked at the relays/fuse in the auxullary fuse box under the bonnet? If so the next thing I would do is a "wiggle test" - put a multimeter on to the terminals where that fuse is and give all the wires around the battery a good wiggle! The earth for the engine management is directly to the battery, and the power comes from one of the master fuses (its always been red on the ones I have looked at) between the battery and the wing.

If you fit a new ECU kit, it won't solve the problem if it is a power supply issue.

Having said that - if it actually is code 23 then you don't have a power supply issue and you have a very unusual fault and an ECU may well sort you out.

I have got ECUs etc (even new ones) if thats the route you need to go down

[V184]

I’ve had an intermittent problem that’s got worse to the point where I only get the van started once in a blue moon. It’s a 2001 2.5L diesel Transit based campervan in good condition (42000 miles) so worth the effort to get it properly fixed.
With the key in ignition position 2 the immobiliser light flashes continuously for 1 minute and then pulses with 23 (I think ECU ID mismatch). Turn to position 3 and the engine turns but will not start. On the odd occasion when the immobiliser light doesn’t flash in position 2, the engine starts immediately.
I have a new battery. Both keys have been read buy a key specialist with equipment. I have tried three different sender units (the unit that wraps around the ignition barrel). I’ve interchanged the ignition related relays and fuses with equivalents in the fuse box. So, something is duff and almost unusable in the ‘brains’ stopping the ignition working (ECU or something else).
I’ve just tried to use common sense so far but I’ve run out of easy options.
Here’s the rub. The camper is in France (Argentonnay, Deux-Sevres region) and I can’t drive it to the UK in its current state. I could have a go a fixing it myself if I had a set of known working kit (ECU, PATS module, Keys etc), or, does anyone know a Transit Guru in France, or, if someone near-ish me in the UK (Salisbury when I’m back home) can def fix this kind of problem I could potentially arrange to get it there.
Any ideas!

Theres a spliced plug fitted to the ring that goes round the ignition check that

[JeffBr]

Matt, sorry I was a bit slack on the Van spec. It is a 2001 Mk 6 and has the 2.4 Turbo Diesel engine.
I've rechecked the code and it def pulses the 23 sequence (unfortunately).
The engine compartment fuse box has a wire with in-line fuse connected through unused slot 32 so I guess thats the 'fiddle' to get the Starter to turn when the van is immobilised. I've tried the wiggle test and no change but I've ordered a new ignition relay (R13) cos I've got a light doubt about it. And ordered new 30amp fuses for the ignition slots. It's France so these will take a while to arrive.
I've got more multimeter testing to do but take another look at the wires coming in to the ignition barrel sender unit, and when the key is turned to position 2 I see voltage on only 3 of the four wire. Do you know if that's normal?
Also done the wiggle test around the battery connections and its in-line fuses.
So far the problem still exists but more work do before I come to you for ECU etc .
Cheers

[MinorMatt]

It would be worth asking an Admin to move it to the mk6/7 section of the forum then!

Sorry but im not clued up on the mk6

[JeffBr]

Yep I will do that Matt, still working out how the site works, thanks for your help. And that's to V184 for the spliced plug suggestion, already on that thanks, cheers