GM Passlock Security Light On – Car Won’t Start

GM passcode security light onI have an Oldsmobile Alero. The car runs great, but here’s the problem. When I turn the ignition to start the car, sometimes it will start right away and on other occasions, the fuel cuts off and I get the security light flashing constantly.

I have to wait 10 minutes until the security light goes off before I can start the again. The car starts right up but it’s very annoying when it’s freezing cold out and this light comes on and I have to wait 10 minutes every time this happens.

What do you suggest?



Hello Nilda,

I have seen issues similar to this and a new ignition key solved the problem. If you have another ignition key, try it and see if that helps.

If it does not help you will need to see the dealership and have them troubleshoot the problem. The ignition key has a chip on it that has to tell the ignition lock cylinder (the part that you put the key inside) inside the steering column that the key being used IS the proper key and allow the engine to start.

I would not go anywhere but the dealer for these types of problems, since most smaller repair shops don’t really have the tools to diagnose this properly and will just waste your time and money guessing.


Thanks for the response. I do have an extra key and tried it, but the problem still exists. I took my car to the dealer and they just guessed and what it could be with no definite answer and several hundred dollars later, I still have the problem.

I just did some more research on the web and here is what they suggest:

Replace the cylinder and Passkey module (you will have to conduct a relearn procedure for the BCM to learn the new voltage value). Here’s the procedure: Lock doors and unlock. Clear codes. Turn key and bump starter, leave on for 10 minutes. After a few minutes the dash light will go out. At that point, turn the key to the off position for 90 seconds to 3 minutes. Repeat this procedure 3 times for a total of 30 minutes and on the 4th try the car will start.

I don’t know if this will finally fix the problem of my car. I will take it to a local shop and show them this and see what they think.


Hello again Nilda,

Yes, that would be another GUESS to try. I would probably replace the ignition lock cylinder (part the key goes into) first and see what happens….just another guess though. Those systems don’t fail enough for most mechanics…including myself to have much experience with them. The dealer will have the most experience, usually.

Posted in: Won't Start Issues

3 Comments on "GM Passlock Security Light On – Car Won’t Start"

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  1. Darnel says:

    I had a similar issue and when I used a spare ignition key the problem was solved. Thanks for your site Austin!

    • By Austin Davis says:

      Yes, always try another ignition key first to rule out a problem with the security chip found on the key itself. Sometimes the ignition lock cylinder (the part the key goes into on the steering column) is the problem as well.

  2. Dan says:

    Broken wires somewhere from the key switch with the pass 2 key reader to the bottom of the column some times moving the tilt up or down will temporarily fix the problem as these wires are small and are often found broken or close to either fix this or look for a pass 2 bypass instructions for your car find the wires at the column base measure the exact resistance of the key resistor and solder in a resistor or a combination of resistors to match the key resistor resistance as close as possible then there you go but beware your insurance company may frown on this if your car was stolen even though the same process is used to install after market remote start system that bypass the theft deterrent system

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