Alarm enabled after wrong key used?

I would try a hard system reboot by following this guide:

https://www.2carpros.com/articles/step-by-step-guide-performing-a-hard-system-reboot-for-your-vehicles-electronics-systems

Check this out:

PASSLOCK MODES
Pass Theft

The pass theft mode is normal operation. During a normal start up, the SECURITY telltale will turn On. The telltale will turn Off when:
a. the ignition is turned to the OFF or ACC position.

OR

b. when the ignition is turned to the START position and a 3 second timer has expired.

Short Tamper Mode (Fuel Disabled Timer Mode)

The Powertrain Control Module (PCM) enters the short tamper mode if the BCM detects an open voltage code (4.43 v-5.00 v). The BCM will send out the fuel undecided password to the PCM. The PCM will disable fuel supply to the engine for 4 seconds.

The driver usually observes a start quickly followed by a stall when in the short tamper mode. After 4 seconds a start may again be attempted, except in one situation.

If the PCM receives the wrong password (example: a new BCM was installed without following the relearn procedure - the SECURITY telltale will flash for 4 seconds and remain On, and the fuel injectors will remain disabled until correct relearn procedure has been completed.

Long Tamper Mode

The Body Control Module (BCM) enters the long tamper mode if the BCM receives the wrong voltage code at an attempted start. The BCM will then send a disable fuel message to the PCM. The PCM will then disable the fuel injectors.

The driver experiences the same start quickly followed by stall. The fuel will be disabled for 10 minutes, and the SECURITY telltale will also flash.

Fail Enable Mode

In the fail enable mode, the engine is allowed to run normally because the fault occurred while the engine was running. The SECURITY telltale will remain On whenever the engine is running to alert the driver there is a problem with the pass lock system and there is no pass lock system protection. The engine can be restarted in the fail enable mode.

Whenever the engine is running, the pass lock system constantly monitors itself. The BCM monitors the circuits between itself and the pass lock sensor. The BCM and PCM also monitor each other through the serial data link. If a problem is detected, diagnostic trouble code(s) will be set and the SECURITY telltale will be On when the engine is running.

This guide may help as well:

https://www.2carpros.com/articles/how-to-reset-a-security-system

Please go over these guides and get back to us.