my car security light flashes?

2008 SATURN ASTRA
110,000 MILES • 1.8L • 4 CYL • 2WD • MANUAL
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MARCELD
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  • 1 POST
my car security light flashes and i can not start my car. when i unplug the neg from the battery, it will start. but when i leave the car, and then try to restart it, the security light flashes once again and it won't start.

do i need a new bcm?
Apr 19, 2026 at 11:34 AM
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STRAILER
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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This means the security system gets enabled, this is why the security light flashes. Does the remote work? Also, do you use the key to unlock the drivers door, both of these actions will disarm the alarm. Also, we should run a CAN scan to see if any codes are present. I would not replace the BCM right now, though it might be the problem but lets do some testing first.

CAN SCAN - https://youtu.be/u-4syLc-ifQ

Please go over this guide and get back to us.
Apr 20, 2026 at 9:18 AM