I have a 2005 Land Rover LR3 4LI V8, had it for about a year now but have only been able to drive it for about the first four months. It was running fine one day and then the next day I get in and the engine cranks and starts, but then immediately shuts off. The same time his happened I got the following faults on the dash.

HDC Fault
Transmission Fault
Parking brake fault
special programs unavailable
amber brake light is on
the suspension is all the way lowered and it won't air back up, if and when I get it started the compressor will come on for about 30 seconds then shut off without raising the suspension.

I have an inexpensive OBDII reader that is programmed for a land rover and I am getting the following faults

U2023- transmission receiving a fault from external node
U0102- lost comms with transfer case control module
U0416- Invalid data received from vehicle dynamics module
B1D12- Volumetric alarm
U0412, U0402, U0100, U0401
there is also a code for the Mass air flow sensor I believe it is P0100

I am able to clear the faults but as soon as I get it running all the same codes come back.

I have changed the batter, the brake light switch, checked the brake lights all work fine, checked the wires under the carpet on both driver and passenger side no corrosion or wetness, pulled the transfer case control module- it had some corrosion and one of the pins had broken off- addressed both of those issues. I HAVE NOT changed the MAF yet, however I did get a cleaning spray and used that with little success.

I am thinking about getting a Gap Tool BT reader, with the assumption that I can update and flash all the control modules and maybe get a more detailed description of the faults.

Please anyone give me some advise or a way to move forward.
Thoughts on the GAP Tool BT and what I plan on using it for.

 

I'm unsure about what you mean by inexpensive OBDII that is programmed for land rovers, but the GAP tool I would think is a huge upgrade from that. It will give you more accurate readout of the faults.
But reading what you wrote my first thought is battery and tail lights but you said you have dealt with that so...

I'm sure someone else will chime in with more experience. Also if I understood correctly when I bought my iiDtool, it is locked to one VIN as far as programming, however it will read codes on other LRs so if you can find someone close that is willing to hook it up to read them in more detail. Just a thought!

 

There is nothing in the system that can shutdown the truck program wise. So if its dying then you have a major issue that is causing it to die. I suspect all those codes are just collateral from all alternator trying to get energized. Basically its starting up and dying too fast so there is a power supply issue (yes, even with a new battery) and those codes just pop up. Its typically for what you describe.

So the issue to concentrate on is why is it dying. The MAF can certainly be an issue but they don't generally fail without warning. So you next thing to check would be the EGR valve. They can fail in a way that essentially causes a massive vacuum leak. Which will make it very hard to start a cold engine and keep a warm engine running properly. You can easily disconnect and plug both ends of the hose from the EGR to test this. The hose connects JUST before the throttle body. Squeeze to disconnect, plug both ends. Try to start.

I would do the above and go from there to rule it out. If it still will not start we can think of fuel pump, etc...

 

Its petrol, so requires spark and fuel. I would check whether you have sufficient fuel arriving at the injectors (one assumes you have fuel in the tank at a reasonable level) continuously, if not possible pump or filter problem. Check battery connections as there might not be enough volts to run everything. Then remove a spark plug and see if it sparks whilst turning over. All of these require a good earth connection. Check the air cleaner as well.