Well an unfortunate update, just tried to start the disco this morning and nothing except Christmas lights in the dash, red, yellow, twinkling green you name it, all are on. Until now no dash lights were on. Plugged my OBD II in and got:

P1668 = Anti-Theft Alarm serial link faultDrive cycle A:Signal out of range - above maximum

found this with a quick google from another forum

https://www.landroversonly.com/threa...e-p1668.28431/

after some standard thread chitchat it looks like the problem is the BCU.

Before I tackle this problem and go the route of exchanging my BCU does anyone have any experience with this code? Again I really appreciate the help on this. This is my first dive into the mystery world of discovery electronics haha.

 

superlock? probably not good.....

 

Alright… I was able to get the alarm disabled and the vehicle remobilised using the 1515 EKA. I’m guessing just a side effect of having to unlock with the key yet being able to alarm and dis alarm with the fob?? Crisis averted so now back to that BCU…

 

Is there still an issue?

 

Yes back to the original issue, no turn signals, door locks including the interior dash button (the physical key in the driver door is the only way to unlock, other doors unlock when opened from inside), or rear passenger windows, at least that is all I have noticed wrong. The key fob will still arm and disarm the alarm. Any recommendations or thoughts on what to check before pulling the BCU? I checked all fuses and they are fine. I do have the leaky sunroof issue so water is definitely an issue. At least I can now pull it out of the street and back into the driveway before I tear it apart.

 

After pulling the Disco into the driveway I got it covered with a tarp so I can stop any further water getting in until I repair the drains on the sunroofs. I was able to get the BCU removed which was a fairly simple job, five plugs and one bolt. No sign of water damage on the circuit board that I can see so maybe a cracked solder??

The plugs on the underside of the BCU

Once the BCU is removed

The removed BCU

 

you have the most recent BCU.

do you have a nanocom? or access to an LR specific programmer? You will need one of these to link the new BCU

You said you tested all the fuses...that does not necessarily mean that continuity is maintained before or after the fuses....but your issues seem to point to the BCU

 

I do not have nanocom but have a shop I can send it to. As far as the fuses go when I pulled the fuses linked to these issues and the BCU other interior components such as the dome light would go out. In my mind that indicates that there would be continuity, but I could also be wrong.

 

I've replaced my BCU.

Here is my recommendation:

Buy a BCU from ebay. If yours has rear AC I recommend you find a replacement BCU that came from a D2 with rear AC. I''m not sure if this is necessary but would not hurt.

Then rent the Nanocom from Extinct in the Sticky threads.

Replace the BCU with the ebay BCU.

The engine will not start since the BCU and the interior fuse box are not synched. Keep the key in the start position for 5-10 minutes and after the small read light on the lower middle of the instrument cluster goes out the truck will now start.

Then you will notice the milage on the instrument cluster is blinking. This means the milage in the BCU and on instrument cluster are not the same.

The Nanocom can turn the blinking off. Technically they are not in synch but there is no real issues with this.

Then you can use the Nanocom to reprogram your fobs to the ebay BCU.

Job done.

 

OP: Just to be clear, you would have to send your whole vehicle to the shop to reprogram the BCU, not just the BCU.......