I have a 2001 Grand Am. In June I had the BCM replaced and by the end of the month my car wouldn't start. I tried resetting the security system by leaving the car in the accessory position for 10 minutes and it worked until today. I got in my car and it wouldn't start. Only difference from the time before is that now everytime I turn my car off and try to start it again later I have to let it sit for 10 mins. I need some help!!!!

Try this:

Attempt to start the car by turning the key to the Start/Run Position.
Observe that the vehicle fails to start and that the security light is illuminated.
Release key to the 'ON/Accessory' Position. (DO NOT turn key to the 'off' position.)
Allow the vehicle to sit with the key in the 'ON/Accessory' Position for no less than 11 minutes.
Turn key to off position and allow the vehicle to remain in the 'OFF' position for no less than 30 seconds.
Repeat #1 - #5 for 3 cycles.
On 4th attempt, car should start.
NOTE : Since this is a fairly long procedure, I would limit all electrical sources, such as disconnecting headlights, to prevent discharge of battery.

NOTE 2 : It is SAFE to wait LONGER than the allotted time, but it is not safe to wait less time. I.e. 12 minutes instead of 11 minutes should be safe; however, waiting 10 minutes instead of 11 minutes is not safe.

Properly executed, this procedure should take approximately 35 minutes to complete.

I used this process to get the car started before. Now, my problem is that I have to go through this process each time I want to drive my car. Also, the car makes a weird hollow thud when it does start. This noise is not normal. Thanks for the help.