chevy malibu theft system

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My father has a 2001 malibu with a theft prevention system. About every 25 to 30 times, the light comes on and he has to wait 10 minutes to start it. Any one have any ideas what is wrong?


posted by  tvhoss

This is a well known problem with the Passlock system. The 10 minute delay is normally because the passlock sensor detected an improper key and will time out for 10 minutes even if you use the right key next. There are various fixes that may or may not work, including getting copies of your key made and trying a different key, replacement of the sensor, and a common fix is to replace the ignition cylinder.
Some have resorted to disabling the passlock system altogether, such as when you install an aftermarket alarm/ remote start.
More info below:

posted by  medicTA

You need to try looking at replacing the passlock sensor that reads the ignition cylinder's resistance code upon key insertion into the ignition switch. I have a 1996 Pontiac Grand am which has lovely GM's passlock I called THEFT SYS and it has caused me some issue with setting up my auto-start functionality. I basically had to wire in a transponder (555L module) that would store and remember the resistance code so that it can feed that code to the IPC when the autostart system actuates the starter remotely with no key in the igntion to do so.

With your problem in the absence of auto start and with you using the factory key, you either have a bad ignition switch or there is a short or something going on in the lock cylinder I would say. That is how I would start diagnosis.

posted by  cmeseadoin

My parents have a 96 Chev Lumina with the same Passlock system. When I installed their remote start, I built a resistor network into the remote start to bypass this system. If you need some more info on how to bypass I can email you it. You could permantly install it to bypass it and it's cheap.

posted by  djsteve

Our friend just purchase a 2001 Chevy Malibu and the theft light blinks and it won't start. Since she is a single mother I wish to help her fix it and would like some ideas. I don't want her to have to pay for something she doesn't need. Your suggestions would be greatly appreciated!

posted by  TerryGearhead

I have a 2000 Malibu. Is it possible to just disable the problematic theft system. Occasionally it won't because of the theft system. After the standard 10 minute wait it will. I've checked sites that offer the module to install if you're adding a remote starter but is there a way to install the module without the remote starter? Or can I get a new ignition switch and install it myself or does the dealer have to do that so the system gets sync'ed with the resistance of the new switch? I just hate to spend several hundred dollars on something as simple as an ignition switch. There has to be a way, right?

posted by  ScottD83

Hi there, I'm a Canadian university student with a 1997 Chev Malibu that has that :cussing: passlock system. That thing drives me insane and there is many a time that I am stuck sitting in my car for 10 minutes in a dark parking lot away from my school while it does its thing. I personally find that more dangerous than my car being stolen. I"m wondering what the simplest way is of disabling this thing, I don't have the money to replace the ignition column, nor do anything extensive, I just want it disabled period. Any assistance would be greatfully welcomed. Thank you very much

posted by  1997Malibuowner

I tried the fix suggested on on this or another forum which was to get some electrical contact cleaner from Radio Shack. I sprayed it into the ignition cylinder and inserted the key about 50 times. So far so good-it was kicking in theft system about every third start attempt and I've had 10 good starts since I did it. I'd give it a try; it's only about 9 bucks for the cleaner.

posted by  powalifta

Good evening, I've read through the posts, I have a similar problem. I have a 2002 Malibu and I've had to take it to dealership to replace ignition switch twice in 2 years. It's looking to do it again. I am intrigued by the post to use an electronic cleaner to clean ignition and the key. Anybody else tried with success or failure?

posted by  QueenMary50

and I have another question..
sometimes I can get the car started, no warning light come on. I'm driving along and then the theft system light comes on. Could this be a start in the system or the computer?

posted by  QueenMary50

These questions are discussed on another forum and a Modification to Disable Passlock is explained in detail with photos.

Have fun!


Proud Member of The Anti-Passlock Club :smoke:

posted by  raycorri

Here's a re-written procedure. You can use this to permanently disable passlock 1 or 2.


The following is a procedure to disable Passlock I or II Systems for vehicles in which remote start/stop system installations are required. This procedure is required because a remote start system will not function with the current Theft Deterrent System (Passlock) which is included on many 1996 and up GM vehicles.

Please note that this modification is intended to be used only in conjunction with the installation of a remote start/stop system and does not provide a procedure to install a remote start/stop system.

If an attempt is made to start a vehicle by a means other than a key rotation in the ignition switch, the Body Control Module (BCM) will interpret this start as a vehicle theft and disable the fuel injectors.

A minor wiring modification may be made to allow the vehicle to be started remotely. This modification includes adding a switch to allow the customer to select “ON” to allow remote starting or “OFF” for normal Passlock operation.

CAUTION: When this modification is performed and the switch is set to the ON position, the theft deterrent feature will be disabled. When the theft
deterrent is disabled the SECURITY/THEFT SYSTEM telltale will light up indicating that the theft deterrent system is NOT functioning.

Refer to appropriate GM service manuals and/or SVMQP Electrical Guideline Manual for instruction on splicing and electrical connections.
1. Select a suitable on-off switch (see note below) which will be used to disable/
enable the Passlock System. Mount the switch in a location such that it is
accessible to the driver and will not interfere with normal vehicle operation.
NOTE: This is an extremely low current circuit (approx. 7mA), it is therefore very important that a high quality, low energy, fast acting switch be utilized
for this application.
2. Turn the ignition switch to the OFF position.
3. Locate the Main Ignition Switch Harness in the Column. GM's Passlock System wires exit the Ignition Switch Tumbler together and then join with the Main Ignition Switch Harness. (See or and select your Make, Model and Year for wire colors and clues on the quickest way to access these wires.)
4. Locate the Yellow Passlock Data Wire which is included in a bundle of three tiny (20 GA) wires wrapped in friction tape.
Cut this wire and splice a 0.5mm2 (20 GA) yellow wire to each end of the cut wire.
Keep wire length to a minimum. Route modification wires clear of moving parts.
Connect the yellow wires to the switch such that the contacts are OPEN when the switch is in the ON position.
5. Turn modification switch to the OFF postion (contacts closed).
6. Start vehicle to verify normal operation. If engine “cranks but will not start"
recheck the switch position (contacts should be closed), wire connectors and
modification wiring.


To enable remote start:
Start the engine with the ignition key (modification switch must be in the OFF
position). Turn modification switch to the ON position (contacts open). The
SECURITY/THEFT SYSTEM Telltale will light up indicating that the Passlock System is inoperative.
Once the SECURITY/THEFT SYSTEM telltale has been on for at least 5 seconds the vehicle can be turned off and then remotely started.

To disable remote start:
The Passlock System can be reactivated by turning the modification switch OFF
(contacts closed). Vehicle can either be running or off when this is done.

Please note that the VCM/PCM will record Diagnostic Trouble Codes (DTCs) related to the security system when the modification switch is in the ON position (circuit open). This is due to the way that the VCM/PCM interprets this condition.

Any condition which removes battery power from the Vehicle Control Module/Powertrain Control Module (VCM/PCM) (e.g. dead battery, disconnected harness connectors, etc.) will prevent the vehicle from being restarted. If the engine exhibits a “cranks but will not start” symptom, place the modification switch in the OFF (contacts closed) position. This will reactivate the Passlock System and allow the vehicle to be started with the ignition key.

Hope this will help some of you!


Proud Member of The Anti Passlock Club:smoke:

posted by  raycorri

well i did it i followed the instrution and it worked on my 97 malibu (been about a week now) many thanks for this annoying problem :thumbs:

and my autostart works as well about 3wks now

posted by  osborste

So if you have a remote starter put in will this fix the problem? Thanks.

posted by  metcalf34

You kind of have to read between the lines. The bulletin was originally meant to be used when adding a remote start. However; you don't have to add the remote starter. The disablement stands alone. The key to all of it is the Yellow wire. If you just quickly want to see if this works---- (1)Start your car (2) Remove your radio, but do not unplug it--just let it hang (3)Reach inside to the left and find the main ignition harness---all of those wires together(4) Find a small bundle of 3 tiny wires (usually Yellow, Black, and white) wrapped in friction tape running from the ignition lock cylinder. See the link to DIAGRAMS. There are some good photos there. (5)Cut the yellow wire (6) Your SECURITY/THEFT SYSTEM light will come on steady (7)The Passlock is now disabled for all future starts.

We just simulated the Toggle Switch disablement. Try this for a few days and if you like it, then go back in and add the Toggle Switch(Just in case you need to reset the system after a battery disconnect)into the Yellow wire. If you don't , then reconnect the 2 ends of the Yellow wire. Hope this helps.


Proud Member of The Anti-Passlock Club:smoke:

posted by  raycorri

I am the not to proud owner of a 2002 Chevy Malibu. My lastest repair is the Passlock Sensor..........a whole whoppin $500 plus the cost of my rental car and tow bill. This lovely GM product has been the worst car I have ever owned!! I think by the time it is paid off in another year almost everything under the hood will have been replaced. I will NEVER again own a GM hunk of junk.......there is definately something to be said about owning a foreign car.....I guess you get what you pay for!!! The American car makers should be ASHAMED of the quality of product that is being built!! I am proud to be American but will never again be the owner of an American made vehicle.

posted by  hrgirl07

I have a 2001 chevy malibu and I have had a couple of hard times trying to start it due to the theft system in the car. I have heard about turning the key in the acc for about 10 to 15 min. Recently the car's theft system went off again and so I put it in acc for 10 to 15 min to reset it. But this last time I did it the theft system light will not turn off. How do I turn off the theft system light?

posted by  Crave2rave420

I have found thousands of complaints about the Passlock Anti Theft System defects. Please take 5 minutes to file a complaint to the NHTS about this matter.
GM does not care about this problem. DO NOT give them anymore of your money. They will not recall this problem. With enough complaints to the NHTS the government will recall this product and make GM fix at their expense.

posted by  ajmj2901

I have a 2001 Malibu may theft system light come on all the time, i have been stranded in numerous places with all my grand kids then have that 10 min wait and hope it will start GMC should have to fix this at there expense. I baby my car and this is really a dangerous problem. Our government should take care of this.


fairygirl20   25 Jul 2012 18:41

G.M. Government Motors? UAW screwed so they screw back they figured. I'm with going back to buying something more simple some how, some way. Too many electronics.

SOSDD   01 Sep 2012 01:44

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