Here is my very unique situation:

My 2005 4.4 LR3 was in perfect running condition, no issues at all. I parked my car at the airport, left for a trip, and when I was on that trip I lost my key. Fast forward 1.5 months later I get a new key from factory Land Rover, and then have a guy come and program the key. This is when things went haywire. The car started throwing all kinds of errors, alarm wouldn't turn off, wouldn't even try to turn over, was completely immobilized.

I took it to a Land Rover specialist they noticed some water in my floor board and told me it was likely water leaking from the sunroof onto the CJB, so I tore it apart and the CJB was completely fine, no corrosion and all the wires were still functioning. So then they told me it was likely the cluster, so I started to inspect that, here's what I've found so far:

Symptoms that support the cluster being the problem:
- The car will not start, even if the key is not programmed the car should start for brief moment then turn off
- Since the first attempt to program the key the emergency flashers and alarm have continuously gone off when the battery is connected, this even after I disconnected, removed, and reinstalled the central junction box
- The door locks will no operate
- No communication with cluster error on the scanner
- Turn signals will not function

Things that make me think it's something else:
- I have played with the harness connector on the cluster to see if it was a connection issue there, it didn't help
- The cluster is still showing my millage, and displaying "System Check In Progress" when I turn the ignition
- The gas gauge functions

I'm getting pretty desperate here, not really sure what else to do. Land Rover and my local specialist told me to junk the car because I'll spend more than its worth trying to figure out the problem, but I love this car, before it stopped running it was in amazing shape body and mechanically, only 120k miles.

I'm open to suggestions!

 

Check your battery. Can’t hurt. If you have too low voltage nothing will work and you’ll get a metric crapton worth of weird errors that will all vanish the second you have a good battery and alternator supplying 14 or so volts after ignition. I had one cell broken once in mine, it supplied about 9 volts and the IPC was lit up like a xmas tree when you moved key to position 1. Didn’t have enough charge to crank and turn the engine.

You haven’t mentioned any codes, you wouldn’t happen to have a code reader would you?

 

Battery needs a charge or replacing

 

I do, I ran them today actually. It's only throwing P0167 (lost communication with the vehicle immobilizer control module).

Interestingly enough when I originally took it to the specialist and they hooked it to the computer it was throwing everything:U0155
U0138
U0128
U0102
U0300
U0151
U0128
U0100
U0155
U0126
U0102

Here is something I found strange. I was surprised when it only displayed the U0167 code today, so I was suspicious that all the other codes it was throwing when the specialist checked it with the Land Rover wouldn't show up on a standard code reader, so I disconnected the cluster, then ran the codes. It threw all the codes I listed above EXCEPT U0167. Not sure what this means, but it has me thinking.

I'll take the battery to be tested/charged tomorrow, I think its something so simple I overlooked it, but it very well could be the issue.