2003 Chevy Impala Security Light And Not Starting

Security light on 2003 Chevy Impala Issues with the Security light & car not starting. At times, it acts as if the car is possessed! We have had luck with turning the key into the start position & waiting 10 minutes & starting again. Yesterday after work, that did not work. I tried that 3 times with no luck. While waiting for a ride home, I tried turning the key one more time & the car started right off. Started this morning & when I left for lunch.

After lunch, the car started but the Security light is on. During the course of trying to start it yesterday, the Security light not only was on but it went from saying Security to low fuel to service engine soon & the battery symbol. I have read so many different things to do online. Is it possible, that I need a new key or a new battery for the remote door opener? I have changed the fuse for the remote several times but it keeps blowing again. Could that be the problem with the lights coming on?

Answer: You have a couple different problems happening, which I can help you with. The security problem is an easy one. You need a new ignition cylinder. The Passlock Sensor for the theft deterrent is part of the ignition cylinder housing and those go bad on the Impala's quite a bit. Once replaced, the vehicle will need the theft deterrent relearned. This will have to be done at a GM dealer to be done correctly. Your other problem with the lights going on and remote problems are due to a bad Body Control Module (BCM). On your particular car, I've seen them do very odd things electrically and have replaced many myself. Again, the BCM will need to be replaced at a GM dealership due to the fact that it will also need to be setup and programmed to your vehicle. If you do both repairs at once, only one theft relearn will need to be done, but if you do one or the other repair, after each one you will need to relearn the theft again.


Shuts Off Without Warning

My chevy impala shut off without giving me any warning lights on the dash

Answer: This could be several things- you could have a bad ignition module, crank position sensor, fuel pump, loose wiring, etc... Would need more information.


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Comments (5)
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  • Guest - David Knight

    My '00 Buick Regal is cranking slow,not starting. Battery has a full charge. Problem happened when car started normal,died and slow cranked like bad battery. Tried jumping,but that doesn't work

  • Guest - Stan

    In reply to: Guest - David Knight

    Could be corroded battery cables or a bad starter. Would need to get a load test done on it.

  • Guest - Justin

    This is a common problem on GM vehicles. I have been dealing with these systems for years. Through much trial and error i have found that BYPASSING these systems is alot more cost effective than trying to diagnose and fix them. The cost is too high and mechanics tend to replace as many things as they can before fixing it. This IS something you can fix yourself as i have done dozens of them for friends and family. Once bypassed will NEVER be an issue again.

  • Guest - david

    In reply to: Guest - Justin

    how do u bypass

  • Guest - Tj wood

    In reply to: Guest - david

    Hi I have a 2003 impala n need help I have had a padlock system problem I'm some way of a mechanic I have replaced the ignition switch n cylinder n have tried to reprogram it numerous times but the security light never stops flashing but some times it will start after key on for half hour but even then it still flashy I want to totally bypass it I got the car for my lol girls first car n she's got to drive it once please help me