1996 x300 immobiliser

My “new” aquisition from Italy is nearly finished now. It has taken about half a year now and the battery has gone flat. After installing a new one she cranks, but won’t start. When the ignition is turned on, the check engine light turns off after a while. If I am not mistaken this indicates the car has been immobilised. So I though maybe closing and opening with the key fob might help, but the key fob doesn’t work either. I installed new batteries, but still nothing. So I thought I would try another fob. I tried programming a new fob, but the valet switch is broken. I pulled it out and bridged the contatcs instead of operating the switch. I am not sure if it was me wobbling and not getting the required 5 contacts, or if anything else is wrong - I lean towards the latter though. Also I don’t think the fob worked when I got the car.
I am a bit lost as to what to try next. I will install a new valet switch, but don’t think that will be it.
Any directions would be appreciated. If I understand correctly, the US cars don’t have an immobiliser - would it make sense to install US control modules to get rid of the problem? What exactly would I have to swap?


Does the Tacho read ~250 rpm whilst cranking if not it likely to be a failed CKPS?

I will have to double check when I get back to the car, but I am pretty certain it does show cranking rpm. Thanks for the hint!

Does an immobilised car usually crank and just doesn’t fire? Or would cranking also be inhibited?

The valet switch is repaired, but still no succes in getting the key fobs programmed. Central locking does not work, and the boot can be opened with the key only.
I checked and I DO NOT get any rpm on the tacho when cranking. But since the check engine light goes off before cranking and the whole alarm system and central locking does not work, I would assume the problem to be with the immobilizer / alarm system. Wich modules control the alarm / central locking and immobilizer and where are they located?


The cps does not throw a code so it could still be the culprit.

And does it also cause the immobiliser light to turn off when it should not?

Sorry not aware of the immobiliser light? Where are you seeing that?

It is the check engine light in the bottom left corner of the instrument cluster. When you turn on the ignition, all the lights come on (as a test) and turn back off after a while. Usually the check engine light schould remain on until the motor is running. If it also turns off, that means the car is immobilised (and that is the behaviour I am getting).


Ok, the garage the car is at right now wants to get done with it now, but they aren’t able to fix the problem. (They have done a very good job of fixing the disastrous paintjob the car got in Italy though). They want to take it to a jaguar main dealer now. It sounds expensive and also I am not convinced Jaguar will still be able to fix this. Do they still have the proper equipment to program keys? Is a WDS system required, or will their new equipment do the job as well?


PS: I have read in another thread that the US cars didn’t have an immobiliser. It seems to be a logical thought to me to convert my car to that system. Is that possible? Would I have to replace the security module with something else? Or replace the ECU? Maybe this is a much cheaper option than letting jaguar have a play with the car…

Just throwing it out here but has the inhibitor switch been checked to see that it hasn’t tripped, this cuts off the fuel pumps in the event of an accident. Not sure if the engine still cranks with it tripped, somebody might know?

No, its a manual…

Even manual cars have an switch that cuts off the fuel pumps in the event of an accident, I am not talking about the transmission inhibitor, I probably used the incorrect term. This is a switch that trips in the event of a hard hit, I have been in a X300 that went over a lump of timber and it tripped the switch. Its normally positioned in the footwell kick panels.

Oh, okay. I have pointed that out to the garage but haven’t doubled checked they Jane actually looked at it. I should make sure.

The car is at the Jaguar main dealer now. They believe the security locking module to be faulty. And they can’t get a new one (I guess that is lucky, it would cost 2 arms and three legs…) Now I need to hunt down a used one. Unfortunately there are A LOT of different versions arround. They all start with LNA2600 follow by CB001 to CC010 or so. I am not even sure wich one is installed in my car, I am waiting on feedback from Jaguar. Does anyone know what the differences are? I wonder if others will work as a replacement.


Some superseded numbers are because they change the wiring connector plug type/shape.
There are probably a lot of other reasons too. Just checked JLR Classics website and they list just two, 001 and 009. Both are listed for Ch 720125>812255.
Good luck

Hmm, to me it looks more like 40 different ones here: https://parts.jaguarlandroverclassic.com/parts/index/part/id/C50.C5074.C5074347.C50743475410/brand/jaguar/

My bad HarryE30, I was only looking at the UK fitments. If you eliminate all the other countries that don’t correspond to yours it will make the list a little shorter.

I know it does. But what is out there on the second hand market is all those listed I guess.
The car is from Italy, I am in Germany and so far I have located control units in the US and the UK.
I wonder if the US ones might work and just have no immobiliser, but the UK ones are obviously easier to get delivered to Germany.
The one installed seems to be a LNB2600CC001, but it is hardly readable.


The listing on JLR Classics seems to indicate that CC001 is the one used on Italian variants.