2002 Chevrolet Monte Carlo



May, 15, 2010 AT 9:34 PM

Electrical problem
2002 Chevy Monte Carlo 6 cyl Front Wheel Drive Automatic 111000 miles

For about two weeks now when I go to crank my car, randomly my security light flashes and the car wont crank. I can wait 10 mins and it will unlock and fire up. So I assumed it was a faulty Passlock system that GM is notorious for having and was going to replace it. However in the last two days other problems have come up. When I stick the key in and turn it, my fuel gauge (possible others in the cluster as well, I will check later) wont initiate, my fuel pump wont kick on and I get low fuel and service engine soon displays. After leaving the key in the ON position for about 45 seconds, everything kicks on, you can hear the relays and fuel pump all active normally and the car will then start. Also since then some of my interior lights wont work (my temp gauge works but illuminates sometimes and other dont), my AC/Heater thermostat lights work sometimes, my rear view mirror lights work sometimes (the lights for the auto dimming mirror power and Onstar). Also my passenger side front corner light/blinker works sometimes and not others.

Could this possibly be a BCM beginning to fail causing Passlock to trip as well as lighting/gauge/fuel pump (and relays) to delay activating? Or more malfunctions caused by the cars ignition switch?

Also I know where the PCM is located on this vehicle, but I'm not sure where the BCM is located. I'm assuming behind the dash somewhere just above the brake pedal? Any and all help would be appreciated.

3 Answers



May, 17, 2010 AT 5:56 PM

If your battery is bad it will do the same thing. The BCM is under the console. Also if you have the diode type system get another key as the diode may be worn out from putting it in and out of the key lock.



May, 17, 2010 AT 9:28 PM

As of this morning 5/17, I've installed an entire new ignition switch (using the existing key lock cylinder). So far no problems at all. When installing I used electrical connector anti-corrosion spray in the pins to help prevent corrosion from the high humidity levels (live in FL panhandle) in the future. I should be able to determine soon if it was the fix. Fairly easy procedure, took about 30 mins.

Battery is maybe 6 months old. Terminal connectors same age (replaced the stock side post terminal for a top post set-up for aftermarket audio). Also I completely disconnected the Onstar system. So those lights are off permanently. My other gauge problems have also went away since replacing the ignition switch.

My anti-theft system is the Passlock with the resistor being inside the ignition switch itself instead of the key. Although from what I gather both styles seem to have problems in certain GM models.

I will update further in about a week after I can determine if the ignition switch was indeed the cause of the issues and replacing it was the resolution. Until then I have a CV axle slinging grease out of the intermediate joint boot and need to replace it. Oh happy days.



June, 12, 2010 AT 8:35 PM

So replacing the ignition switch solved the security " Passlock" problem. Havent had any issues since.

Far as my intermittent lighting issues, I found a bad ground connection that when got wet, caused some of my lights on that circuit to not come on. Cleaned the connection and no problems there either.

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