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Joel, Auto technician
Category: Chevy
Satisfied Customers: 1603
Experience:  GM, ASE Certified Technician. Chevy, Buick, Pontiac, Olds. Over 18 Years experience and growing.
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My 2001 chevy impala wont start at times. The security light

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My 2001 chevy impala won't start at times. The security light is blinking and it eventually starts in 10-15 minutes. Had a diagnostic test at a chevrolet dealer and they said to replace the Body control module at $498 or the passlock cylinder at $370. They weren't sure which one but I can only afford one. Please tell me which one

Hello and welcome.

Well, the most common cause for a security light and the car to not start is the Passlock cylinder.

This is a common failure on many GM cars.

The fact that it starts after 10-15 minutes leads me to believe this is your problem.

The waiting is basicaly a relearn of the theft password, which tells me the BCM is functioning and able to relearn the password XXXXX Passlock sensor gives it.


Not to say i have not had a few BCM's cause this over the years, but 98% of the time it is the Passlock sensor.


Actiually, since it is so common, when we have a problem car and can't descide which one is bad, we ALWAYS do the passlock sensor first. Almost always takes care of problem.

Hope this was helpful,


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