A bad door lock would not affect the alarm system but if the door lock switch is not good, it can.
Using the key in ignition should be good enough to disarm the system and since it is not working, check the fuses to see if any is blown.
Next try closing all doors and use the key to lock and unlock driver door to see if it works.
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Sunday, August 9th, 2015 AT 5:18 AM