just spitballing so you may have tried this, but have you tried swapping in a new crank position sensor?

 

Just my observation, but if the starter is cranking when you jumper the relay, then it's not going to be the ground cable (unless someone here knows something I don't). Cause by the starter turning the engine, it tells me you've got a good enough ground to spin the starter. So, back to basics. To get an engine to run, you need fuel, compression and ignition. Pull a spark plug wire, stick a screwdriver in the plug wire and lay it next to a good ground source. Crank the engine and watch for spark(s). If no sparks, then my guess is something fuel related. Compression, you said it previously started, so I'm guessing you're good there. I know I'm not much help, but I'd start looking at the big 3 and go from there. Glad my relay jumper trick is working for you though!

 

Agreed, didn't think there was a ground issue but was easy enough to verify.
Like I mentioned, when starter relay jumpered, engine spins at a high enough rpm.
The one time It did start, ran smooth and sounded great (as did my old LR3), just had multiple faults displayed.

It HAD fuel, spark, and compression (based on previous LR3 running sound).
Something wonky is happening.
This is my 5th LR in 11 years....not going to let this one beat me! lol

Thanks for your response, much appreciated.

 

Just posting this because I wonder if its simply a funky key or such.


IMMOBILISATION

The immobilisation control module receives information from related systems on the vehicle and passes a coded signal to the ECM to allow starting if all starting parameters have been met. The information is decoded by the ECM which will allow the engine to run if the information is correct.

The information is on a rolling code system and both the immobilisation control module and the ECM will require synchronisation if either component is renewed.

The ECM also protects the starter motor from inadvertent operation. The immobilisation control module receives an engine speed signal from the ECM via the instrument cluster. When the engine speed exceeds a predetermined value, the immobilisation control module prevents operation of the starter motor via an integral starter disable relay. For additional information, refer to Anti-Theft - Passive (419-01B Anti-Theft - Passive)

 

Wish I had a second key to validate the system.
Thanks for the info!
Found the previous owners address, maybe I will drop them a line.

 

If doors lock and unlock with the key, the key should be okay

 

So on Sunday I turned the key....nothing as usual.

Jumped the starter relay, bam! Starts immediately.
Left it run for some time and noticed initially the radio and HVAC system worked (still had many lights illuminated on inst. cluster)
Then radio and HVAC stopped working and hazards began to flash.
Then the HVAC and radio began working again....was listening to the Bills game lol

Any ideas?

Also I started looking at codes codes using my 4D can software tool.
I COULD access the:
air suspension module
petrol engine module

well everything but: petrol transmission module.
4D would not open this module.

Most reading indicated loss of communication with ECM and TCM

Interesting the air susp module specifically lost com with TCM

 

Tried once again to start tonight, nothing with the key.
Jumped the starter relay, again fired right up with hazards flashing then off.

So I pulled the TCM (purchased from a wrecking yard) and installed the original TCM

Key no start.
Jumped the starter relay, turns over but will NOT fire.

Put replacement TCM back in.
Nothing with key.
Jumped the starter relay, turns over but will NOT fire.
ok, what gives?
Thought it would at least start in a limited state again.

Electrical gremlins?
Lucas electric haunts from old parts in garage?

The only wiring I haven't validated is behind the radio, which I suppose is next.

Thanks for your time...
hopefully I can post a solution soon.
stay tuned

 

Agreed.
Doors do indeed lock and unlock with key.

Thanks for your confirmation......needed for my sanity :-)

 

You have checked cabling/connectors from ignition switch to ECM, as jumping start relay and and the engine runs, indicates loss of a connection. When you turn key off does engine stop straight away?