2004 Chevrolet Monte Carlo Security Light and Won’t Start

Hey, I have a 2004 Chevy Monte Carlo. My security has locked the car up. do i have to take the car to GM to get a Passlock reset or can i do it myself?

Mechanic JK
Is it physically locked and wont turn, or does it turn and the car won’t start?

It turns and the car won’t start. I’ve replaced the fuel pump and ignition module. Still nothing. Finally i took it to a shop and they told me the security is locked up on it.

OK. The most common problem with this is the key cylinder. It is also known as the Passlock Cylinder. A new one would need to be coded to your key, then replaced and the system relearned.

Do i need to change both the Passlock cylinder and key? or can i get a new key?

The key is not the problem, it is the cylinder. You can use your old key if it looks in good shape.

OK cool, thank you.


2004 Chevrolet Monte Carlo

Can i take my Passlock out? bypass it? The car has not cranked for a full minute since 12/24/201.

Anything is possible, but we don’t recommend or tell you how to bypass factory security systems in this chat. You should get the problem fixed, it’s probably a faulty ignition cylinder/Passlock sensor.

Question…9-10, is it the ignition cylinder? The security has the car locked. Is this a common problem in Chevy cars? Do i have to take it to GM to have it fixed b/c its not pulling any codes.

Most of the time it is the cylinder causing the problem, probably 99% of the time. You don’t necessarily have to take it to a GM dealer to get it replaced, but it does need programming which is easier and faster at a dealership. Also, you’re probably not pulling any codes because the scanner you are using doesn’t communicate with the body control module which controls the theft deterrent.

OK. wow! you know i’ve spent soo much money trying to fix this issue and no one i’ve taken the car too has told me this. I had to google to get an idea of whats wrong with my car. Thank you for your help. I’m going to bite the bullet and take it to GM…DANG!

Glad to help!


2002 Chevrolet Monte Carlo. My car wouldn’t start when I turned the key in the ignition switch. So I checked my fuses and my crank fuse was blown. Then I changed my crank fuse and the car started right up and after 5 minutes the fuse blew again.

You probably have a short inside the starter assembly or the wiring going to the starter. Sometimes even a bad ignition switch or relay can pop that fuse, too. It would take some looking into, and eliminating things as you go along. The most common thing would be a problem with the starter itself. You may want to get it checked by a technician.


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9 comments to 2004 Chevrolet Monte Carlo Security Light and Won’t Start

  • mike

    2001 Chevy Monte Calro will not turn security light on reseting still no go when car siting headlights blink and drains battery is there away to disconet alarm.

  • Alan

    I have the same problem with my 2003 2 lock cylinders later in 3 years..it is still there.

    Security light is on and it a crap shot sometimes whether it will start,,,,,

  • Pam

    I had to pull the dash to change the heater coil in the 03 monte carlo, now it will turn over and not start. Do you suspect that I have engaged the security system to lock? will unpluging and removing dash parts result in security system lock down on my MC? and i have tried all the “kitchen sink” techniques for re setting the system, none of them work.

  • Aisha

    I have a 2004 Ss Chevy Monte Carlo dat want start the security light is flashing I turned the key forward for about 15mins and its still doing tha same thing can u tell what I can do about this

  • Bajram

    Yes, the ignition modlue when first failing will cause the engine to die when it warms and start back up after it has a chance to cool (not necessarily cold.If the chack engine light is on, it would be a good idea to have the codes scanned to see if there is a misfire present. If there is a misfire and a loss of coolant, you may have a . You can scan the codes your self at home. Here is how to do it along with code desciptions:

  • dale

    I have an 04 Monte Carlo is, I tried to start it and it won’t crank, and the security light and check engine light is on

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