Hazards lights

Hi all,
so I have a 1999 discovery 2 TD5 I've owned for the last year now and have loved every min until last Sunday when me and the Mrs went out and the land rover opened fine started it up and the hazards started to flash I turned it off locked it unlocked it and tried again but still the same result.
so been checking on here for the answer. but draw a blank.
I have put a new inertia switch.
I've changed the hazard light switch.
I've had all fuse boxes out and checked them for damp or any signs of corrosion but all are fine.
so I've had to pull the fuse for the time being.
so the land rover starts up unlocks fine and locks back up fine.
this morning when I got in and turned the key the locks did a cycle like I locked the car and opened it.
the central locking works fine from the key.
I've disconnect the battery for a couple of hours.
locked the car and unlocked 3 times from the door top set the alarm off.
but i am now at a loss of where to go next.
any help would be much appreciated.
I've worked on cars for 16 years and I am now at a complete loss.
I am also a M.O.T tester so have use of a garage and a lift

@sierrafery will possibly give you a lead on this?
But nice to see that a Vehicle Mechanic is also stumped

Kev

Thanks kev.
The next step is to pay a auto electrician to come and have a look but thats going to be expensive might be worth me doing the course myself It would work out cheaper lol

but then it I thought to my self get on the forum and ask for help everone needs a helping hand now and then.

May be cheaper to get yourself a Haynes Electrical systems manual??
As it does look like an electrical issue!

I've used mine a couple of times, and picked up an easy problem ( I.e. where I could fix it)!?

Or if you have not already! A fault finding system??

Kev

Hi, the easyest would be to get a known good pre-facelift interior fusebox and swap it cos even if there's no visible sign on it doesnt mean it's OK and this fault looks very like a IDM misbehaviour. Just disconnect the battery negative lead first then after the swap and battery reconnection turn ignition on 2 and let it so 5 minutes before you do anything else.

Evening thanks for the reply.
So I have been and got a second hand interior fusebox which I no came off a running disco with no fault code and the same thing is still happening.
Where to next?

Once the IDM is ruled out then unfortunately for this symptom the next suspect is the BCU but that one needs programming with dedicated diagnostic tool it's not plug and pay

Thanks for the reply would a nanocom scanner be able to code a second hand bcu back to the car. Also I might sound stupid but does the disco 2 have a 10as unit if so would it be worth while changing them both.
Thanks agian for all the help

Yes, a nanocom unlocked for D2 can synk a good used BCU(provided it's not immobilised) and there's no 10AS unit the alarm and immobiliser are both BCU + IDM functions

Thanks agian for the reply
do you mean if my discovery is not immobilised or the second hand bcu unit is not immobilised. I really do apprishate all the help. Thanks agian

I mean the second hand one to be in perfect working oder removed from an unlocked vehicle cos you can't program an immobilised unit

OK brilliant thanks agian.
You don't no anyone near Doncaster that has nanocom do you. Saying that iam willing to travel if you no someone. That could help me out. Obviously they would be paid for there time.

I'm far from UK .... if you replace the BCU dont try to crank it before it's programmed cos you immobilise it... after the swap you have to go with nanocom in the BCU to set it for the vehicle's equipment and synk the fob(s) or set the alarm to "not fitted" then in the engine ECU menu - "utility - learn security code", only after everything is set is allowed to crank it

I have no personal experience with them but maybe worth a try to contact these guys cos they seem to be able to fix the BCU and send it back as to fit it without any programming: https://www.ebay.co.uk/itm/133115857675

So just thought would update.
So been and got a bcu unit and had it programed in and still the same issue.
So with the nanocom plugged in and it came up with a fault with the immobiliser so it was all down to the immobiliser.
Thanks for all the help and advice.

The immobiliser can be a fault in the BCU or IDM(part of the interior fusebox) nothing else and as long as it starts and nanocom can "talk" with the BCU it's not immobilised...i'm affraid that there is some botch in it's electrics made by the PO which triggered this fault, if you have access to nanocom and connects to the BCU you can disable the immobiliser or set the alarm to "not fitted" then the immobiliser is completely disabled also there is a setting in "alarm-others" for "Hazards - disabled" which will not bring them on if it's immoblised . Go in emulator here https://www.nanocom-diagnostics.com/downloads in "Td5 - Valeo BCU - settings - Alarm-other" to see what options you have without risking to mix up completely the vehicle's "mind". Good luck cos you'll need lot of it as the BCU and IDM were ruled out

Good info on this post. It just helped me to fix this issue on my 2000TD5. I think it was the inertia switch, as I felt a small click when I pressed it the first time. It didn’t seem like it was fully triggered, more likely partially triggered? I pressed it again to see if it clicks every time, but it doesn’t. So I am reasonably confident that pressing it did something.
I didn’t know there was any half way tripped switch on this. I thought it was only triggered or not! (When triggered it kills the fuel pump, as far as I know).
I did lock & unlock it, but I had done that multiple times before, so I don’t think that didn’t anything?
My car was running as normal, just the hazard lights going on all the time no matter what. 30 minute journey and everything seems normal again.

I must say I hadn’t heard of this issue until it cropped up. I thought I had already attended to virtually every possible weak point/ fault these can get, but apparently there’s yet more to come!