This is my first post. After many years of lusting I finally bought a 1997 xk8. It’s in excellent condition but I’m doing a number of “upgrades/mods”. How ever I noticed the keys that came with the car are totally different to any I’ve seen on videos etc. after much searching I discovered they’re from a cobra security system. They lock and unlock the car remotely but I have to insert the key in the ignition to stop the alarm. I bought a proper key and followed the method to sync with the car but I can’t even get the car to enter the reprogramming mode. After the head light flashing there’s no beep or light on the J gate. Any ideas before I try buying a new locking security module?

 

I assume you mean keyfob, rather than key? Have you got the correct fob for the car?

If the Cobra fobs lock and unlock the car, the system has obviously been butchered at some point to install the Cobra alarm so you probably need to dig into that. Can you post pics of the Cobra fobs and the Jag one you bought?

 

Before trying a new module it's worth doing a few checks on the existing one, including if the aerial is connected and you can also try resoldering some pins on the RF receiver board in the SLM (pictured). There is a very good thread on this if someone else has it bookmarked. Michaelh is the expert, maybe he has the link?

 

 

Every car I have dealt with if I did not install these security systems they cause problems. I have spent lot's of hours removing these just because I never could be sure if the install was done correctly and if the system was still working correctly.
I would not start replacing modules until you understand what was installed and how they did it.
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I'm curios as to why an aftermarket system was fitted, when the car has a perfectly good alarm system - until you find out what is going on with the Cobra system there is no point looking at the 'Jaguar systems'.

 

From what the OP has said the Cobra alarm is working perfectly, it's the OEM Jaguar fobs that won't program.

I would imagine the Cobra is wired into the driver's door lock switches, which is why it requires the key in ignition to stop the alarm sounding - that is standard behaviour if you open the car with a key rather than the OEM fob.

The issue is almost certainly the SLM and the previous owner nuked the problem from space by installing the Cobra rather than twatting about with the SLM. At least that's my guess given what the OP has said.

 

I would double-check that the cobra installation didn't require any of the OEM wiring to be disconnected.

For the SLM 'fob programming' mode, try this process posted by atikovi:
https://www.jaguarforums.com/forum/x...98/#post495772

You may need a few attempts to get it to work, and note that, for me, the LED on the gearshift only flashes once.

There are various other checks you can do - this is the thread that dibbit referred to:
https://www.jaguarforums.com/forum/x...4/#post1721719

I'd also check that the fob is actually transmitting something - if you know someone who is a radio amateur or has a scanner capable of UHF reception, then they should be able to confirm that. The European frequency is 433.920 MHz, idiotically placed in an amateur band...

P.S. Our older fob type takes 2 x CR2025 batteries.

 

thanks everyone. A few things ton check.