Sparky-88

Hi All, new Forum member here. Looking for help regarding troubleshooting the Security circuit on my '02 Monte Carlo. Every so often the Security warning light comes on. No obvious cause. Eventually it goes away. Hasn't seemed to cause trouble, just a nuisance.

This morning the car would not start. Battery and Security lights were both flashing. The starter would not engage; no cranking whatsoever. All other electrical gadgets appeared to work normally. Based upon another 'Security' thread, I assume the Security light and the no-start condition are not directly related. Sounds like the Passlock system cuts only the fuel supply. No connection to starter circuit, correct? A few minutes later, the car started normally. It happened while my wife had the car; I haven't had time to check it out directly yet.

But since I obviously have some problem with the security system, I'd like to troubleshoot possible causes and get that resolved. From the previous Security thread, I found the following:

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The components of the Passlock System are as follows:

The ignition lock cylinder and key
The ignition lock cylinder case (including the Passlock Sensor)
The ignition switch
The Body Control Module (BCM)
The security indicator (on the instrument cluster)
The Powertrain Control Module (PCM)
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If I bring to car to the shop, can a diagnostic be run which will help isolate what is triggering the Security warning light to turn on?

Are there any other sensors related to the security system that could be malfunctioning and causing the warning light to turn on?

A separate but related question... I'm wondering if / how the trunk is tied into the security system. My trunk no longer really pops up when I press the 'open trunk' button on dash; it unlatches but stays down. Lifting open the trunk after locking the car doors then sometimes triggers the alarm. I'm wondering if some security-related sensor in the trunk could be causing Security circuit issues?

Any thoughts are greatly appreciated.

johnphan

I am having the exact same problem with my 02 Monte Carlo turning on the security light and battery light and not allowing it to start. What did you find the problem to be with your car?

Sparky-88

Never found an exact cause. Recently purchased a bypass module (normally associated with remote starters) to bypass the security system. I haven't installed it yet so can't say whether it will really be fixed.

BTW, in case you don't know about it, there is an operational work-around if the Passlock system locks up on you. Turn the key to 'On' and leave it there for AT LEAST 10 minutes. After 10 minutes, try starting. It has always worked for me after one time. But I've heard others say they needed to try it up to 3 times.

The Passlock malfuncion is apparently a common issue that has never been addressed by GM (as far as I know). Probably never will be since it's not a safety issue.