You can also test the SKREEM module by locking the car and then looking through the glass to see if the red LED is blinking on the tow-away switch in the center console. Leave the Tow-Away anti theft switch/alarm on for this quick test. If LED is blinking SKREEM module should be OK. No blinking and you have a problem with the SKREEM (Sentry Key Remote Entry Module). I am assuming the siren is not going off because the batteries in it are long ago dead.