Spare key fob won't start engine

NO CAR TOLD AT ALL, MAKER, MODEL , YEAR.
SO ALL ANSWERS WILL BE WRONG, GENERIC OR WILD GUESSING.

1: CAR CAME WITH 2 FOB'S BUT all BAD NOW? OR LOST 1?
YOU SAID Remotely BUT HOW FAR FROM CAR IS REMOTELY 2FEET?
ALL Inside car door lock switches all work?
ok key part works and engine runs and drives perfectly
all fuses in the car are good as in ALL FUSES>
the fob batteries must not be put in upside down
my cars for sure 5years up the fob buttons are just bad.
my 2010 car , on 3rd set now, for worn out buttons
i dismantle bad fobs fully and the gold contact area of the switch looks like a
shotGun blast or eat up by acid.
totally normal on fobs. used every day endless. (body sweat etc)
buy new fobs and get them programmed in , is the cure.
YOU SAID SPARE FOB, IS THIS THE DAY1 NEW CAR WORKING GOOD THEN FOB FAILING NOW?

listed checks
FUSES ALL GOOD
SCAN THE PCM FOR ERROR FOR SURE AFTER A FOB FAIL TEST.
GET NEW FOBS. AND PROGRAM THEM TO THIS CAR , SECRET.

try reprogramming it by sitting in with doors closed switch ignition on then off 5 or 6 6 times until a beep then press any button on remote to program you may have to repeat on spare keys

1. check battery's condition.
2. try starting it with your spare key.
3.if started with spare key, then you need new chip in your main key.
good luck.

Replace the battery in the remote.

Close the doors. Lock the doors using the buttons on the key fob. Use the fob to again unlock the doors. The key should then work the ignition. If this will not work, you will have to tow your vehicle to the dealer and buy a new key and/or fob and have it programmed to the vehicle.

Try not using the fob at all open the door with the key. And start the jeep if it works without issue then its the fob. If its still not working correctly remove the battery from the fob and try again(since if it was damaged could be sending the signal for the panic button) the next step is the key try your spare security key can become worn and cause issues with the antitheft system. After that it only leaves computer problems and those can get spendy

If the car goes "beep beep" when you try to lock the doors something is still open.
otherwise
Sounds like a defective keyfob try a new battery, try your spare if you have one.
If you don't have a spare you should get one anyway.
You can match your new keyfob to the car by following instructions here:= http://www.bluejag.co.uk/X-Type-keyfob-reprogramming.php

yes it has a battery ,but not sure if just renewing the battery will make it work again,i changed both my batteries on my remotes (spare) without any problem.for
my sovereign

The battery in your remote key fob can be changed.But the spare key has to be programed to work.Take your main key to the dealers And have them do it for you.

I am assuming your problem is similar to mine; the key fob isn't dead, but for some reason the boot won't release.  This happens rarely, but can be very frustrating (and embarrassing)!

When neither the key fob nor the release on the boot work, lock and unlock the car, and insert the key into the ignition.  Turn the key to the second stage, i.e. the accessories are powered, and then remove the key.  This ought to allow you to use the fob again.