The battary in my spare key for my 2004 jaguar x type went dead while it was in a drawer. I replaced the battary in the key and the remote doesn't work. The remote in the primary key works fine. How do I reprogram the key?

towed home, right, and battery is 100% full dead or bad.
read the manual, on new keys (alien)
this is no year 1980 and back sorry !

the IMMO must be happy.(and sure is not)
a new key must be married to the car per the manual
this maker of car has no self (DIY )key programming (2nd ,or 3rd from one good key) sorry NONE>

the answer is here

• The Manufacturer decided to not produce this vehicle with self-programming capabilities.
• You must get an Automotive Locksmith to program the remote to your vehicle for you.
• If your vehicle requires professional programming we tell you, so you're not left with any doubt and searching all over the internet.
• It's still much cheaper to purchase a remote from NorthCoast Keyless and get it programmed by a Locksmith rather than buying from a Dealership!
• We strongly recommend calling a Local Auto Locksmith for help here.
• Find a Local Automotive Locksmith instantly by using our search tool below:

same answer for any car that lost the 2 good keys new car day1.
same.for aLL IMMO cars,with the IMMO security lamp not happy
and the blinks say ?BAD KEY)
and the scan tool told you error DTC KEY FAILS.

You may need to remove the back seats and try reaching in with a long rod/bar, and unlatch it.

Have the remote start removed from the vehicle. Fix the cut wires. Use the key.

if its the correct key for your car and its not working try a spare if you have one. check the condition of the teeth on the key it maybe worn out or bent. it could also be the key tumbler that is worn and needs replacing. does your key chain weigh a lot that is more than the weight of say just 4 keys if so this may have caused the tumblers to were out.

Replace the battery in the remote.

You need to get a spare key, or have a locksmith get the trunk open for you.

Sounds like a dead battery. To verify, try jump starting -if it starts with a jump then you need a battery.

Jags use a car immobizer system to prevent theft. look in your owners manual to find actions you must take next. Keys shouldnt need reprogrammed, but Im not sure with a Jag

It may not be the battery, it may be the ignition switch. There is a switch within the key barrel if this switch gets dirty the remote lock, I have a 2004 model. Squirt some WD40 into the key barrel and turn the key a few time to shift the dirt, then try the remote. The switch is design not to lock the doors accidently, so the switch has to closed, when you take the key out of the barrel.

YOU NEED TO REPROGRAM IT