Security light on

Try this 1st if it doesn't work have to go to GM to program it
make sure have battery fully charge as it will take about 20 min or so
try to start engine
engine will start for sec and fail
leave key in on position for about 11 min or until security light stop blinking
turn key off wait 10 sec and try again
same thing wait 11 min or until security light stop flashing
key off 10 sec and try again
security light off key of 10 sec it should start