I have jumped the inertia switch with a paper clip and it made no difference.

I checked the 95' specific diagram and there the Reader/exciter connector cable count and colors corresponded. So i have checked all the wires in the green circle on the attatched image for continuity and they all had about 0 - 0.5 ohm.

This should mean that there is no broken cable there? But that does not explain how, before i took of the tape surrounding the wire harness i could make the car start or not by pulling the harness and/or moving the steering wheel. Since i removed the protection tape around those wires in my first post that trick has not worked. I am at a loss.

Is there any other wires under the steering collumn besides the ones in the attatched diagram that could be the culprit?

Wires in the green: R= 0-0.5 ohm.

Jumped inertia switch.

 

Ha! I must’ve not have read that part before. I have experienced something very similar, where I have tugged on the cable and changed symptoms. Then I spent many hours trying to track down signals on the cable for shorts and opens figuring I must have a broken or intermittent wire somewhere. After struggling on my back up underneath the dash and trying to remove connectors in places, my hand can’t fit and probing wires that I can just barely see I found everything appeared to be OK. no amount of cable wiggling would re-create the result I previously had it never showed signs of a problem.

I was having a problem with trying to reprogram the front electronics module where I got a previously intermittent communication fault, which at some point of me messing around turned into a permanent communication fault.

Since I knew the communication phone had to do with the bus, I was paying attention to the bus lines. Since the bus lines, a delicate signals in needed to be solid copper wires that are twisted together to illuminate noise coupling onto the lines I thought maybe I had, some portions of the cable that were allowing noise in it. The only place that I could happen really is where the wires are and twisted going into the connectors. I found a couple places where there was about 2 inches of untwisted wire right at the connector for front electronic module.

without anywhere else to go, I twisted those bus wires without disconnecting anything or pulling the pins from the connector. I just rolled my fingers over the wires and put it all together. Then i crossed my fingers, sacrificed several small animals to the Jaguar Gods of the Network Bus and hoped for the best.

and wouldn’t you know it -the communication fault disappeared.

even after I put all the trim back together, It continued to work after installing the kickplate under the driver‘s side dash and the sill plates along the driver side door bottom sill, and the instrument panel access door on the driver side dash (facing the door)

so, if nothing else you can try that

 

I believe these are the pictures of the connectors that I was working with

 

Last resort on the immobilization is that Andy can modify the engine ECU to remove the inhibit

With that piece of information, the final or close to final component is the engine ECU

So the deduction would be the signal to the engine ECU

I;ll look into it later

I understand the fiddling with the connector changed your situation.to go bad to start with

Pins and sockets not migrated away from the face of the connector halves ?

sockets do not look deformed , you can't really do a grip test unless you sacrifice another connector or source a new pin from a vender

The question is does the chip in key come in different resonance frequencies and what component has to match the chip or if the frequency is only 1 across the whole production.

 

You didn't say whether you tested the cable from the Security module to the ECU, as per the last page in my PDF?

Also, if there is no pin for ground on the Reader/Exciter module, then I assume it must be grounded through it's body - so check that is a good ground.

Beyond that I'm out of ideas. You would need to get some more sophisticated tools - Jaguar IDS can do some interrogation of the Security module. A Scope may help in sniffing a signal on the data wires? I don't know.


Good luck with it.

 

I agree with that ,just put a test lead on the metal case of the control module to a known good car frame ground and should be close to 0 resistance

The engine ECU has a dedicated heavy wire external case ground strap other than some connector wires having a couple of grounds , off the top of my head those small connector wire grounds are on the engine firewall inside the engine compartment side

I need to read Brendans document

In removing the tape, you may have changed the state of a wire signal and the immobilization may perceive that as someone trying to trick it and subsequently lock or freezing the system

Hard Reset ?