D2 won't start, immobiliser seems ok but no fuel pump and hazards.

Hello landy lovers!

Had these issues for weeks, have read many threads with some similar problems but not completely and have tried many things but it's getting on me nerves now. If anyone has suggestions of things to look for and try I'd be very grateful but I'm not sure what questions to ask so here's what I've done so far, more or less...

So the d2 td5...all was good then developed a missfire/lumpy loss of boost so done injector harness, cleaned ECU connectors and ran lovely, sweet!
Next weekend it wouldn't start and the hazards come on so started researching. It opens on the fob fine with both keys, no alarms and it cranks but can't hear the fuel pump prime first (new fuel pump went in last year but it was a cheapish one) so I bridged the inertia switch and it started, opened and closed the doors and hazards went off, done a few laps round the block and seemed alright but problem repeated if the bridge was removed.
Couple weekends later I've gone round the block again with the bridge in but hazards came on while driving then it cut out reversing onto the drive, couple weekends later is today and I've fitted a new inertia switch and the problems still there, opens on fob all good without alarms but ignition on and the hazards are on with no fuel pump prime. Tried the eka code key trick which went in correctly but still didn't prime pump so I feel like immobiliser is alright and the alarm does work properly.
I have nanocom and when going into the bcu settings the hazards stop but still no pump, If I select inertia to no hazards and write it (it says writing to ECU) they don't come on at all. When I try reading engine faults nanocom won't connect to the ECU.
I'll be changing relays when the local places are open on Monday. Todays tests were done while jump leads were connected to my running van as the battery was running low so there was 14v while trying it. There was good voltage going to fuse10 for fuel pump but I'm unable to pressure test it.
It's looking to be pump related or wiring between it but as its not started, then ran fine, then not started again and so on I feel like it functions ok when it does come on and is probably 8 months old.

My friend has his immobiliser bypassed and alarm disabled with some box thingy so I'm leaning towards that but would rather do it properly if it's possible.

I hope this could help towards solving a specific problem I can't seem to find answers for or pointing in the direction of answers

Hi, it's not the immobiliser for sure, that one would not let it crank, the problem is on the inertia switch's circuit somewhere between the plug and main relay or in/at the fusebox so the ECU doesnt get feed hence no communication with nanocom, check fuse F13 first, replace relay R9(main ECU feed) with R8(heated screen) or R3(headlamp wash) to rule it out, if no joy remove R9 and bridge the perpendicular cavities see if it starts then or if nanocom connects to the ECU... if it does and the relay is 100% good check continuity between the parallel cavities and inertia switch's white/green wire and for voltage against body on the brown/black wire, if you have voltage there plug the inertia switch back and check for voltage across the parallel cavities of R9 with ignition on 2, it must be 12V there if no voltage check against body to see what's missing cos it should be 12V against body in one of them(parallel cavities), if that circuit is OK check voltage on fuse F1 and if it is then the problem is probably in the fusebox or the connector is loosen or corroded so investigate that, eventually jiggle the fusebox with ignition on maybe it reacts to that. If still no joy we'll speak again just concentrate on what i said and do all those tests exactly.

Thanks for your reply! I'll crack on with that and see what happens. I red a post of yours earlier about checking fuse f10 for voltage and tried it over a few other fuses with them matching battery voltage, also seen a video with someone's relays working when half pulled out but not fully in. Tar very much, will let you know!

Good luck... if the circuits are all oK then i'm affraid that the ECU is fubar cos that's a possibility too, even though that would be a bit expensive it's better than some hidden wiring issue o that circuit which can be a nightmare to find

Hello, thanks again for the help! I've done all that today and here's what happened...
Swapped r9 with both other relays and it was the same, no pump or start and hazards on. Bridged r9 perpendiculars and pump worked, car's now running and it connected to the ECU with nanocom (read it with no faults) but hazards were still on. Drove a couple laps of the estate to get a bit of battery charge in. Turned it of and on again and the 3 amigos popped up but will ignore them for now.
Checked continuity through parallel relay ports to inertia switch which was ok and there was voltage at the inertia plug to body matching battery.
Checked voltage across the parallel connectors on relay 9 and it was less than 12v (readings were jumpy) and fuse 1 was 2.odd volts. Removed fuse box, all connectors are in but quite dirty so I sprayed contact cleaner on them, stripped the fuse box and was no visible corrosion or breakages.

What's so special about what the relay does for it to run ok with it removed and bridged? I'm looking at the relay being the problem but the others didn't work either

Forgot to mention as well, this weekend when trying things the rear drivers side door stopped unlocking on the fob. The driver's door done this about 8 months ago but dismissed it as a common fault that didn't bother me too much as it didn't seem to effect anything.

R9 delivers the main ECU feed through F1, once bridged the ECU gets the voltage and the pump as well but the hazards are coming on cos the circuit is open on the coil, the problem is somewhere on R9 - inertia switch - ECU circuit as R9 doesnt close on ignition hence the pump relay gets no power to the coil... if the fusebox is 100% good the ECU is suspect too unless it's a frigging wiring issue in the engine bay harness, at this point you should understand the diagram if you want to troubleshoot further to see why R9 is not triggered, R9 is R100 on the diagram, see at engine management second page where the inertia switch appears, at the fusebox the parallel cavities are the coil and the perpendiculars are the contact, you shoud get solid 12V on the coil with relay in situ cos even if you get voltage without relay the voltage can drop under load if it's a weak contact or electronic ECU issue... if you remove R9's cover and force the contact on with your hand it should run without hazards... if you are not skilled enough to work after the diagram the ECU and the fusebox must be ruled out https://www.dropbox.com/sh/47hbz40an5he5j2/AACVo2MkgpDEHVVEGyLYFJzna/Circuit diagrams 00MY RHD.pdf?dl=0 ... good luck

Righto, cheers for the info! Might take a while to get my head around it all but it looks like there's enough to go by and I could definitely do with learning it. I wouldn't rule out some dodgy wiring harness as you could almost climb through the inner arches and it's been submerged in mud a few times so it's a bit messy.