Shak8

Thanks @Fudderin. I had done that but it was not that. It was because of one of the rear doors that was shut but still triggering alarm. Had to open and shut all the doors and windows and then used the Lexus FOB to arm and disarm the security system. That worked.

Thanks @Chc0318, even when I insert the keys in the ignition the alarm still keeps going on

Alarm sounds continuously when I reconnect the battery terminals on my 1993 Lexus LS 400. How to disconnect the alarm?