Does anybody know what is needed to replace the ignition cylinder?
Every once and a while, the car thinks the key is in the ignition and the doors won't lock and the chimes will go off when I open the door.

 

Do you think this is related to your headlights staying or going on as was suggested in your other thread?

 

Could this be a faulty Key Transponder (a.k.a. Exciter Ring)?



These used to be extremely unreliable on the XJ40 although I haven't come across a report of a similar issue on the XK8.

Graham

 

Or is it just the little keyhole 'door' sticking open (a known fault)?
That can be fixed with graphite spray, apparently.

 

Thanks, I will get some graphite spray and check.

 

I am not sure, could be related.

 

I am NOT even going to comment on the name, but does the ring set off the chimes w/key in and door open?

 

JTIS has the procedure for the key cyl replacement. Looks pretty easy. My ring seems to cause a lock-up of the security system when it doesn't detect the key...everything goes dead, chimes and all. JTIS does't seem to go much into it, but a dealer a few years ago told me my "voltage measured low" at the exciter. Since it's intermittent, I've been living with it. Requires a reset at the battery, then all is good until next time (wife with me, pouring rain at night,dressed for a wedding, etc). My reading of the schematic shows that the key-in switch is responsible for the chime when the door is open so graphite that little flap door as suggested. Probably sticking open.

 

As Mike says, JTIS is very shy on information about the Transponder / Key handshaking procedure. The Transponder is what recognises the chip in the Key and allows the ignition cycle to operate. Exactly how it does this isn't described.

If you do go for a replacement cylinder, you'll have the additional trouble and cost of having the new key mapped to the vehicle unless it's possible to order an identical cylinder to the original from Jaguar.

Graham

 

I would hope that the ignition switch would be like other MFG's, where you can program the ignition for the original key.

Thanks everyone for the info, going to try the graphite spray first and then go from there.

 

I know this is an old thread but I just found it and thought I would bump it and see if you had any luck with the graphite spray? I'm having the same exact problem with my car and used some de-icing/lubricating spray but it did not solve the issue. Still seems like the little trap door is stuck and will only stop chiming when I bang on the lower portion of the dash and the chime stops and the info screen below the speedo finally goes dark. The weird thing is the alarm still will not arm itself though which is strange... Hope someone will chime in... Thanks in advance! Joe