chevy cavalier theft system

There are four different components to the passlock lock cylinder, Actuator assy, lock cylinder,preload spring, and switch assembly. What part did you replace? New or from a junk yard? The four components probably aren't interlocking correctly or were not installed correctly. Why was it replaced to start with? Worn Key?

I changed the whole swithch assembaly, i had another cavalier that i got the switch out of, the reason i changed it was because it was wore out, the switch wouldnt turn over. but when i changed them i had to cut the original wires and splice the others into it, because they didnt have plug ins. i was wondering just because if it was a diffrent year car that i got it out of the computer wouldnt reconize it, it was only off maybe a year. i appreciate the help. thanks

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This makes no sense. ALL GM ignition switches have plugs that connect them to the electrical harness, they may snake down to the under dash area but they are there.
The different year doner car could very well be missing some anti-theft components if it was older than your car. It also possible that you're just suffering a coincidental failure of the passlock sensor at the ignition switch, or that you mangled the passlock sensor when you made the repair.

you said there was a chance that there could be a failure of the passlock sensor, is there a way to check or change the sensor, or do i have to change the whole switch, the doner car was either the same or one year newer.could you tell me where to look for the passlock sensor. i appreciate it. thanks

I suggest you try to find a service manual so you can read and understand how the passlock system works. It sounds like you have damaged it to the point you may have to get all four components to restore it. Parts of it go in both sides of the column and cutting/splicing wires can really create problems. It is possible if the original lock wouldn't turn a little lock eeze would have fixed it as the tumblers were probably just stiff...

could you somehow explain how to change a passlock sensor, i think that it is in the switch itself, but not sure. is it hard? thanks

would anyone know if a 1988 honda accord 4-door windshield is the same as a 1989 honda accord 2-door. thanks for the help

I don't know about 96 Cavalier, but here's a quick, easy, free thing I learned for my '99 Suburban (it would start - then shut-off) that worked. After spending 4 days of my vacation getting my car repaired, including all of the electronics in the steering wheel. It turned out to be the security system detecting that my car key was 'fake' thus someone must be stealing the car. Since it has to do with anti-theft, Chilton's and other manuals didn't even discuss it. However did provide some useful info... and along with the following tip from the parts store guy the Suburban finally would start every time:
Here's what I did that worked:
Set the ignition key switch to accessory - the electronics are ON in the car, then remove the negative terminal from the car battery for a few minutes. Then, turn the to OFF, hook up the battery and you're done! As it was explained to me, this causes the car to erase its memory, so it has to re-learn the car key. This worked when all the steering wheel repairs and everything else didn't.
By the way, the anti-theft stuff was confused because I plugged a GPS receiver into the cigarette lighter, and the GPS had a battery in it. This slightly changed the voltage sensed by the anti-theft device - causing it to think my car key was a 'fake'... Removing the GPS didn't help at that point.
Good luck,
Tom
I changed the ignition switch in my 96 cavalier and sometimes when you go to start it it wont start, the theft system light will come on.or when its running it will shut off and you have to give it a while then it will start. but you cant hear the fuel pump kick on when you try to start it, i was wandering if there was a relay switch that you would have to push.

I also have a 1996 Cavalier, the tumblers froze up in the ignition so it would not turn at all. We purchased a used ignition and a friend installed it into the car. Now the car will start but will not stay running. We tried the thing with turning the ignition on and unhooking the battery cables. It did not work. Is there anything thing else short of taking it and (being taken by) the dealer? The car is in excellent condition and runs excellent, it is worth the bother. Please help if you can. Thank you.

You have Passlock 1. Attempt to start the vehicle. At this point, if the vehicle starts, and the security light has not illuminated, a relearn is not necessary, and you?re done. If the vehicle starts and stalls, leave the key in the ?Run? position and wait for the ?Security? light to turn off. This will take approximately 10 minutes. At any time during this relearn, the light may flash or be on steady. If the ignition switch is turned off at any time during this relearn cycle that the security light is illuminated, the entire cycle must be restarted from the beginning. For most cars, one cycle will be sufficient for the relearn. If the vehicle will not start after the first cycle, then continue the process from step #3 to the end. Most trucks will require that you continue from step #3 to the end. 3. When the light turns off, turn the ignition switch to the ?Off? position for approximately ten seconds. 4. Next, repeat step 3 two more times for a total of three cycles. After the third time, the new code will be relearned on the next start attempt when the ignition switch is rotated from the ?Off? position. 5. From the ?Off? position, start the vehicle, observing the security light. If the vehicle starts and runs normally, and the security light is off, the relearn is complete. If the vehicle does not start, check for trouble codes before proceeding further.
After this, if you continue to have intermittent problems, you may want to consider Passlock Disablement. There is no need to add a remote starter for this to work.
PASSLOCK I or II DISABLEMENT
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.
CAUSE 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.
CORRECTION 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 disable Passlock 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 or THEFT telltale will light up indicating that the theft deterrent system is NOT functioning.
PASSLOCK MODIFICATION 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 orhttp://64.85.6.118/diagrams/diagrams.asp and select your Make, Model andYear 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 ofthree 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 cutwire. 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.
SWITCH OPERATION
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 or THEFT telltale will light up indicating that the Passlock System is inoperative. Once the SECURITY or THEFT 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.
NOTICE 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.
Dog