S40 2.0d won't start - nightmare!

[Madmax123]

Hi all, new to the forum and this is my first post, wish it was under better circumstances but I've had some major trouble with my 07 s40 2.0d.
Had it a month and was having some starting issues where it would start and die before eventually starting, did the throttle body mod and serviced it, checked all stuff I've seen on here and online and eventually noticed some air in the fuel lines, here's where it got really bad.
I sent it to have the filter housing and lines changed, after that it wouldn't start, turns over but nothing, gave error code ecm-1213 and had a bad injector, fair enough then I'll change the injector, still no start.
Went to another garage who then said the immobiliser is not deactivating and needs a new ecu, 1400 quid! Not viable so got it home and sent the ecu to Ecu Testing who told me they haven't the facilities to work with this model (sid803a Siemens)
So getting it back tomorrow, I've ordered another used ecu to clone to but a few people I've spoken to have said it doesn't seem like an ecu issue, there's no immobiliser message on the dash and the ecm1213 would fall in line with the one bad injector.
Should have ecu back tomorrow so will try with new injector but I don't have much hope.
The codes showing are p0380 for glow plug relay which it's always had, anti skid message which it's always had and the new ecm-1213 code.
I really could do with access to a VIDA to get better answers but can't find anyone to help and can't get the car to volvo or afford their prices, already out £350 so far and no closer to a working car. it seems its likely the ecu is somehow damaged in the injector driver circuit but no way to know it seems.
I can't get my head around this immobiliser fault they said as there's no error message or code for it.
I initially thought it was just air in the system but I've since spliced in a priming bulb and got all the air out and also checked every wire in the injector Circuit, injectors, earthing points, shorts, fuses etc and doing nothing obvious, checked cem for water or corrosion, nothing obvious.
Has anyone experienced anything like this?
Immobilised with no dash message?
Ecm-1213 Crank no start?
Ecu damage with 1213 code etc.
Any help would be greatly appreciated, I'm at my witd end and close to giving up on the car, can't afford to keep going with it as all the stress is messing with my health and disability.