I'm a newbie and I love the forum. I recently purcahsed a 03 Impala LS and I love it. I have a problem and was wodering if anybody can help. My security light is constantly on while driving and was told by the dealership that it could be the Ignition cylinder or the car possibly had a remote start at one time and has a bad wiring connection. Of course I would like to start with the inexpensive way first and check to see if there's a bad connection, problem is I don't know where to look for a bad connection. Any ideas on where to look? Any help is greatly appreciated! Thanks,

Brendan

 

pull the knee bolster apart, and check the wiring thatleads to the back of the key cylinder. Or just look for a module that doesn't belong down there. Here is a blurb that i am cutting and pasting from the service manual.....


The Passlock™ sensor and ignition lock cylinder are one assembly. The Passlock™ sensor is separate from the key and lock cylinder. The key and the lock cylinder work together in order to determine if the proper ignition key was used to start the vehicle.
In the event of an open Class2 serial data line between the BCM and the PCM, the vehicle will become fail-enabled if the PCM has already received the password from the BCM for that ignition cycle (the engine is running). In this event, the following conditions occur:[align=left]



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The SECURITY indicator will be ON continuously.[/align][align=left]



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The PCM will become fail-enabled for future ignition cycles.[/align]If a failure in the Class2 serial data line occurs before the ignition cycle, when the PCM is not fail-enabled, the following conditions occur:[align=left]



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The PCM will never receive a valid password in order to enable the fuel injectors and crank relay.[/align][align=left]



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The vehicle will not start.[/align]




So basically, check the wiring between the bcm and pcm

 

Thanks for the advice. I will try that tommorow and update this thread. Thank you.

Brendan