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Ignition and Security Warnings in '04 Chevy Impala

A year ago, I had a problem starting my car (a 2004 Chevrolet Impala, about 120,000 miles). When I put the key in the ignition, the engine wouldn't turn. I knew there wasn't a problem with the battery because my lights, radio, etc. were still operating fine. Instead, I got a bright flashing "SECURITY" message on the front panel of the car. After a few minutes pacing around the parking lot, I returned to my car and it started without a problem. I checked online, and several car forums and articles claimed that this was a common problem in 2004 Chevrolet Impalas: some faulty wiring in the security system would stop the car from turning on because it thought you were trying to hot-wire the vehicle.

After the first incident, I didn't encounter this problem again until recently. Within the last 2 weeks, this problem has become more frequent, occurring maybe 2-3 times per week. The car won't start and I'll get a flashing "SECURITY" message. If I wait a while (between 5 to 30 minutes), the car will eventually start.

I finally decided to take my car into a Chevrolet dealership to get the problem fixed. I described the problem to the mechanic; she guessed that the cause was associated with the ignition cylinder, and said that it would cost a minimum of $750 to fix ($100 to check for the problem, $650 to replace the cylinder).

I'm only a college student, and this is more than half my paycheck for an entire month (ouch!!). Before taking out a loan to pay for this, I thought I'd try to solicit some second opinions. Is anyone familiar with this problem? Is the problem associated with wiring or the ignition cylinder? Is there any way to haggle the price down from $750?


  • For future reference....Just because your lights and radio work..a non-start problem could still be the battery. Starting a car requires HUNDREDS of amps..while running the lights and radio only require MAYBE 20 amps.

    But I don't think this is a battery problem because you're able to start it after a little while. Batteries don't fix themselves.

    Sounds like the car has a built in Security system. It could be this or it could also be the ignition.

    It's difficult to diagnose a problem like this over the internet. Instead of going to the dealer...find a good independent....should be cheaper. There might even be one in your area that specializes electrical problems.
  • Google PASSLOCK and find hours of reading enjoyment (assuming you enjoy poking sticks in your eye;). I've fixed dozens of GM security issues from the early days of VATS to the PASSLOCK II system. You can fix or even bypass it for much cheaper than the dealer quoted. Since you're young, in school and looking for a frugal repair, here's one example to get you started-
  • The OP says the engine doesn't turn...does that mean turn, as in crank, or turn over? I don't own anything with Passlock but I thought the system shut off the fuel pump on offending attempts to start the vehicle...shouldn't the car crank and run for a couple of seconds and shut off?
  • Lots of people describe cranking but not starting as won't 'turn on'. Later, he says 'won't start' so I believe it probably is cranking but not starting.

    The key point is the security indication on the dash display. That only happens when the system detects a fault.

    I have never seen a GM PASSLOCK vehicle start even momentarily when a security issue is indicated on the dash.
  • Weird there is no edit icon in the mobile version...

    I meant to also say that the ECM inhibits more than the pump. The injector pulses and ignition are also disabled. It wouldn't be hard to defeat if all you had to bypass was the pump and those other functions are easy to include making it much harder to bypass by hot wiring.
  • edited October 2012
  • This happened to my daughter's 2007 Impala... Including the SECURITY message on the display. A new battery fixed the problem. While that may not be your problem, it's an inexpensive place to start.
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