Just to clear up one piece of bad information in this post- The SCLM does not control the key transponder,so look elsewhere to re-program. Ths SCLM can be replaced without any reprogramming, but it is highly unlikely to resolve your issue. I suggest you try and reach bob- (motorcarman) on the forum and get his advice.

 

Agree I don’t believe it to be the security module.
I believe the issue to be in the BCM or ECU, apparently the jaguar shop and his auto electrician cannot talk to the system.
The only codes that come up are the 1260 security and a can P 1797 trans to ECU problem.
i believe the security code has come up from me dragging it onto a trailer.
They checked the trans inhibitor switch but will check it myself.
This is the only jaguar I own that has been able to beat me so far where I have had to ask for help from a garage.

 

The fuse link nuts get loose causing electronics problems

The fuse link is just after the positive battery post called the protection something

Next would be a Hard Reset

Somewhere you may have gotten the SLCU out of sequence and locked up out of sorts

The hard reset brings the SLCU and others to zero state like a computer reboot

The hard reset works on both the SLCU and the BCM ( for the starter relay command ground ) as they are wired hot at all times

The hard reset is to remove both battery cables and bring them together with the battery terminals isolated

Works better on the SLCU if the battery cables are touching each other overnight with your jumper cables

Place a cardboard box , old shop towel , or your neighbors dead cat over the battery post so you can lay down the jumper cables

This will reset your engine ECU so it will take some time to relearn its perimeters

Another possibility is the battery may have been installed backwards , all you have to do is touch the battery post

This will pop some fuses

Ask me how I know

 

The battery was not shorted from the jump start, battery charging and finally being replaced.
All main power leads and connections have been checked with no issues.
Hard resets have been done for up to an hr.
The ford trick of leaving the ignition on for over an hr, battery charger needs to be connected to prevent drain.
This is a ford fix for some of there cars from this era as our system is a hybrid of theirs.
None of the solutions have worked.
i will try the hard reset overnight as I have nothing to lose.
My next step is to pull the ECU and check the internals for obvious damage and test the components.
I will post updates as I go.

 

Yes car no crank resolved and car now runs. Yes a long time not running but I have been away working in PNG.
Finally found a very competent non Jaguar dealer or specialist.
A key specialist, issue was the 1 key scrambled its brains and would not talk to the KVM after attempting to jump start.
Wiped old keys from the system and reprogrammed 2 keys via Jaguar SDD car fired and runs perfectly after sitting for 2 years.

 

I am certain that determining the issue was a relief and that fixing the issue made you smile.
Key programming can be daunting unless you have the right equipment/experience.