This symptom usually infers that your alarm system is in valet mode. You can confirm this by verifying if the LED on your dash/antenna is illuminated solid. If it is you can get your chirps back by turning valet mode off. This can be done in one of two ways:
1) On older systems the valet switch is a stand-alone switch usually found towards the bottom half of the driver side dash. We are unable to tell you exactly where this switch will be because the installer can mount the switch wherever is convenient. When you find this switch simply turn your key to the "on" or "run" position then back off and then tap the valet switch one time.
2) On newer systems the valet switch is built in to the antenna. The antenna is usually found on your windshield. The same process applies once you locate this type of valet switch. Turn your key to the "on" or "run" position then back off and then tap the valet switch one time.
Please see the attached document for photos of the different types of valet switches we have used on our systems over the years.