The key fob for your PT Cruiser controls the locking system by using a wireless transmitter. You can lock or unlock the doors without using the main ignition key and you can also set off an alarm by pressing the "Panic" button on the key fob. The remote is powered by a small battery that will eventually go dead. Save money by purchasing the correct battery type and replacing the old battery on your key fob.
Take a dime or small flat head screwdriver and insert it in the ridge on the side of the key fob. The ridge is on the flat side near the "Panic" button.
Twist the coin or screwdriver until the two sides of the casing pop apart.
Remove the coin battery and look on the front of it for the battery type number. Models before 2005 use CR2016 batteries; 2006 models and beyond switched to CR2032 batteries. Write this number down.
Look online at a key fob replacement website or else call your Chrysler dealer for information on purchasing a replacement battery. Or visit hardware stores that carry lithium coin batteries. Look for the model number you wrote down in Step 3.
Insert the new lithium battery back into the remote and snap the case back together.