Hello!
My 2001 Jaguar XJ8 is having an usual problem when I turn the key to electronic mode it turns on all interior dash lights and will make a compilation of sounds. After the first time if I try to put it into electronic mode it'll be comepletely dead. I can't get any codes from the computer, as it is dead when I try to turn it on, it will not crank at all. Prior to this problem I had unhooked the battery to do some gearbox work (work that has nothing to do with the security). I have tried to unconnect the battery several times and rehooking it to try and reset the computer, hasn't worked. Fob sometimes works, not always, red light above the gear illuminator usual flashes. Help!

 

Have you measured the voltage on your battery?

 

Sure sounds like a dead battery.