Morning all, yesterday I checked all the fuses and relays hoping to find some faulty items, but no faults found. Problem is the CHECK ENGINE LIGHT goes out with ignition lights. The car also doesn't go into keyfob programme mode no matter how many times I try. Its leading me to suspect a faulty module (either ECU or security), however Im not sure if you can replace these items without dealership coding, any info on this would of course be greatly appreciated. Also if the key is used in the door lock there is no sign of alarm activation (lights or horn). I read that you can wind drivers window down, lock car and reach through and open from inside to trip alarm but that doesn't work either, no response. Im new to Jaguars so need a little help here, thanks.

 

Quick update, stripped out central locking control module (behind filler cap) and ECU (drivers footwell) to check for water ingress but all seems really good. Cleaned all contacts and put back together, still no crank or central locking (using key or fob). Im now thinking that maybe the ignition barrel would be my next port of call as I have read that if the small key entry gate is open or faulty then the car wont start nor will the central locking or alarm work as the
ECU thinks the key is still in the car??? will post up findings tomorrow as the footballs on tonight ;-)

 

Yes, the question of a ignition barrel being faulty/sticky has come up in a few threads recently .... have to wonder if winter cold temperatures cause this issue to show up more often this time of year as things start sticking.

Anyway, have heard suggestions of using some graphite lubricant and/or a clean with some electrical contact cleaner (plastic safe).

.

 

Well after many hours I am no further forward. I have bought another BPM with same codes and suffix, still the same. I am now thinking it must be to do with the key and associated transponder ECU under the dash, however I will need to buy this to test. Im not sure if I would be best buying another main ECU aswell to try at the same time, really dont want to start chucking parts and money at it but I have had little to no feedback from you guys and Im near getting ready to rip it to bits and flog it. All help and suggestions will be greatly appreciated. :-)

 

Out of interest , I have a very similar problem, with a 1997 xjr, I have been searching how to reset the immobiliser, and have been informed that a lot of problems can happen with the fuse box connections in the engine bay under the fuse boxes, also there is a bulkhead connection which feeds everything and this is prone to becoming non conducting it's at the bulkhead next to the auto box, also check the multi plug connections below the drivers side fuse box that can become corroded .. It may be worth a try , I can understand the frustrations, I have been struggling to resolve this issue as well

 

Also I have been told to check all the earths as well as these can cause real problems .

 

Bigmad/Scott,

Most of these cars in the rest of the world don't have the immobiliser. You are in the UK right? Perhaps your main dealer or indie can reprogram it? Many of us here have no experience with the immobiliser feature. Let's look for advice from some other UK members.

 

The Check Engine Light (CEL) is output by the ECU. If this does not remain illuminated after the other dash lights go out when the ignition is turned on then the car is immobilised and will not crank or start. When the ignition is switched on the ECU will perform a number of checks (I don't know the detail or sequence) and security is just one of these. If any of these checks fail the CEL will not be illuminated at the end of the sequence.
Have you checked for any error codes?
A fault in the security system will not be easy to locate.
The components are -
1. The transponder in the key
2. The coil around the ignition barrel that energises and reads the key transponder
3. The exiter module under the dash at the LHS of the steering column. This drives the coil, reads the key and passes an encoded signal to the Security and Locking Control Module (SLCM) in the boot.
4. The SLCM identifies the key and passes an encoded signal to the ECU to release the immobiliser if the key is recognised.
There could be a fault with any of these components or their interconnections.
The security system cannot simply be disabled.
The SLCM must be programmed using dealer level equipment if it is replaced.
No programming is required for the exciter module - they are a low cost item on ebay but I think they are fairly relaible.
Make sure the battery is good and fully charged.
Unlock the car and disconnect the battery.
Wait for a few minutes.
Reconnect the battery.
Insert the key in the ignition and switch on.
Does the CEL light stay on now?

 

Guys,

Thanks for the advice , my car is in a storage area , so I have real problems getting it to a dealer I have carried out a number of checks and have the following information

1) when iginition switched on the tachometer jumps to 250 rpm and there is a clicking from a module below solenoids on left hand front and also from around fuel rail.. Not the starter solenoid , but a module below with a thin braided hose coming from it pointing to the inlet manifold

2) I ran the code checker and got a code of P1791 , which reads as ignition source failure

3) the code reader Also details that the engine is turning over at 261 rpm .

I am so fed up with this car , and it's a beauty as well , your help would be much appreciated

Thanks

Scott in Scotland

 

Thanks for replies guys, I have checked next to every component on the car thus far and still drawn a blank. Next step is to wait for replacement ECU, key with transponder and matching exciter module and matching sclm module. Hopefully then I can start to see some progress. Will keep yous updated...

 

Hello folks, I have the same issues with my XF, any one ever resolve the issues?
my VIM ( Vehicle Immobillizer Module ) is down and I need to to find the module itself.

the best I could get from the dealer is the module is in the dash between the driver and passenger seat.

in the meanwhile I have all the same key problems ect ect.

 

oops just realized the model difference. darn these google searches.

 

Not sure if my problem was the same but this is what I did as posted in another thread:

https://www.jaguarforums.com/forum/x...-crank-152412/

 

I have a 1995 Jag the ignition was messed up so the alarm wouldn't set so the immobilizer kicked on the ignition switch is fixed but how do I reset the immobilizer

 

Would a locksmith be able to bypass the immobilizer so engine would start?

 

The immobilizer has 2 issues that come to mind :

The enable from the Security Locking Control Module or SLCU going to the BPM which commands the starter relay has a digital wire that must pass through the BT4 connector located above the fuel tank

It looks like this and used on other parts of the car

The connector has a overcenter locking bar than can migrate loose and lose pin connection

It is a pain in the *** to get seated properly as the sheet metal cutout gets in the way

don't try too hard and break the locking pins

you can use a tywrap to secure the overcenter bar so it doesn't come loose again

The second point is the location of the SLCU being under the fuel fill cap in the trunk behind the trunk liner

This SLCU can get wet if the fuel fill well does not drain properly or there are holes in the well skin

It is a bolt on well so should ge easy to replace if needed or the drain lines can be cleared

 

There is what is known as a hard reset of the SLCU as it is hot at all times from the battery and solves some issues

This involves more then just removing the positive battery cable for some time

 

Hi. Did you solved? I have same problem .

 

I’m looking forward if this is solved too.