GM Passlock Anti Theft System

[clembrewer]

I have an '05 Malibu Classic that I've owned for about 3 weeks. I purchased it used from a Nissan dealership.

The car has refused to start on three ocassions, and I periodically get a theft warning light on the dashboard.

I have one factory key and one copy. If the car refuses to start it takes 10 minutes to allow the system to reset.

What could be triggering this? I want to get more information about this system before I take it to a Chevy dealer to get looked at.

 

[johnd]

Is it the key with the resistor in it? The contacts in the front of the lock mechanism may be dirty or otherwise not making good contact. Rather than replace the lock ($) you can splice in the correct value resistor where the wires exit the steering column. Considering the newness of the purchase, I'd make them fix it unless you bought it "as is."

 

[cousincletus]

If you bought the car at a GM dealer, the car has a 3 month, 3K bumper to bumper "Certified Used Car" warranty on it. Don't know how that works if the car wasn't bought at a GM dealer, though. If not under warranty, you could go to a place that installs remote car starters and get them to disable the Passlock. The symptoms of the anti-theft system going bad are when you start the car, it acts like it wants to run but stalls out just after it starts.

 

[clembrewer]

Yeah, didn't buy it at a GM dealer. I don't believe the keys have a chip in them. There is nothing visible in/on the key, and one of my two keys is a regular metal $2 cut key.

Cousincletis - Good idea. I may look into getting it disabled.

 

[clembrewer]

JohnD - think an electrical cleaner might work? an MAF cleaner? Curious.

 

[rat]

Sounds like you need a new passlock sensor which is part of the lock cylinder, part number 12458191. Quite common from what we see around here. Make dealer pay for something, even half as its not very cheap.

 

[rat]

Sorry, the part number changed to 15822350. List price is
$187.56.

 

[RedDart]

clembrewer: It sounds like your ignition lock is going bad. If the lock fails it will activate the Theftlock system and you will not be able to start the car and be stranded. That happened to our 2002 Chevy Impala. It is a fairly well known problem. I also recommend that you have the car dealer pay for the repair while you are still in warranty. It is quite an expensive repair and the new lock cylinder has to be programmed to work with your keys. Your best bet may be to stick with OEM key blanks as aftermarket key blanks may not have the required specs. Good luck.

 

[The_Jeff]

I'm pretty sure the passlock system takes ordinary cheap $2 key blanks. The system works entirely within the expensive ignition lock system. Any slug that can turn the lock will start the car. I have this in my 2000 saturn. There are hall effect magnets that sense the lock cylinder properly turning and I can see those going on the fritz.

Passkey systems put some logic/resistor in the key blank and is used on camaros etc that are more theft prone.

Regardless the fix is the same as described above and probably must be made at the dealer so the BCM can be properly programmed to the new ignition switch.

Obviously GM marketing wanted to confuse the issue so one would think they were getting more than they get.

 

[brianl703]

Quote:

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I'm pretty sure the passlock system takes ordinary cheap $2 key blanks. The system works entirely within the expensive ignition lock system. Any slug that can turn the lock will start the car.

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This is correct, and the Malibu Classic uses the PASSLOCK system. There is nothing special about the key. In fact, if you were so inclined, you could just bypass it entirely by using resistors wired in place of the ones inside the ignition switch. (You must measure the ones in the ignition switch with a multimeter and then use a resistor of the same value).

That's how remote start systems are wired in these cars.

 

[JMK]

rat & brianl703, are dead on, my local dealerships have told us (Remote start install shop) to completely shut it down on all Grand Am's & Impalas we see. We never did before out of fear from dealership wrath, but I guess they see many of them they want us to fix them before they have a chance to fail.

 

[clembrewer]

Excellent information - Thanks!

 

[mstrjon32]

If the car has less than 36K miles, you're still covered under the original GM bumper-to-bumper warranty, so just bring it in to any GM dealer and they should take care of you.

 

[JTK]

Quote:

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.. you could just bypass it entirely by using resistors wired in place of the ones inside the ignition switch. (You must measure the ones in the ignition switch with a multimeter and then use a resistor of the same value).

That's how remote start systems are wired in these cars.

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If you are out of warranty, that's exactly what I would do. Purchase a Passlock II bypass module from any of the aftermarket remote start makers to splice in, set it and forget it! They are simple to install.

Joel

 

[clembrewer]

JTK - Thanks for the info.

I tok it back to the dealer (Nissan, Ford), they ended up taking it to a neighboring GMC dealer to fix it. They replaced the entire ignition lock cylinder. $420 that I didn't have to pay.

Works fine, but I would have rather they just disabled the system.