How do i disable the anti theft system in the 2001 chevrolet blazer,so i can start the vehicle. I previously asked the question about the neutral safety switch!!

Anti-theft system can keep vehicle from starting , Alarm is for vehicle content theft , open door without key alarm sounds (horns) ! PATS - passive anti theft system PATS enables and disables the engine from starting ,it will not cause the engine to die ! You have some other kind of problem ! If the vehicle engine doesn't turn over an red light on top of dash flashes fast ,then you have anti-theft system problem !
PATS differs from the perimeter anti-theft system in that PATS enables and disables the engine from starting. If equipped, the perimeter anti-theft system protects the perimeter of the vehicle (doors, hood and trunk) and sounds an alarm.

Hi Carol , do you mean PATS passive antitheft system ? Locked up your car ,do you mean it won't crank over an start ?
The passive anti-theft system uses radio frequency identification technology to deter a driveaway theft. Passive means that it does not require any activity from the user.

• During each vehicle start sequence, the ignition key identification code is requested by the vehicle protection anti-theft electronics.
• If the key's ID code has been programmed into the system, the powertrain control module (PCM) (12A650) is signaled to enable the vehicle to start.
• If the key's ID code is not programmed into the system, or if no encoded key is detected, then the powertrain control module is signaled to disable the vehicle.

The passive anti-theft system communicates the state of the security system to the powertrain control module via the J-1850 communications network data link connector (DLC). The powertrain control modulebased on the communications from the passive anti-theft system, will determine if the vehicle's engine is enabled to start. The passive anti-theft system differs from the active anti-theft alarm system in that the passive anti-theft system enables/disables the vehicle from starting and only operates with the ignition switch in RUN/START position. The active anti-theft alarm system has perimeter protection capabilities and operates only with the ignition switch OFF. Refer to Section 13-11A for active anti-theft alarm system information.
Vehicle Disabling The passive anti-theft system will be activated and disable the vehicle from starting if any of the following conditions exist:

• damaged encoded key
• unprogrammed key
• non-encoded key (key has no electronics)
• wiring concern
• transceiver concern
• Passive Anti-Theft System (PATS) control module concern
• J-1850 Communications Network concern
• Powertrain Control Module (PCM)

There is no fuse for the anti-theft system ! It receives it's voltage from the BCM . Do you know what a BCM is ? It is a Body control module .
The Passlock?"¢ System is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate or the ignition switch is operated while separated from the ignition lock cylinder case. If starting is attempted without authorization from the Passlock?"¢ System, the powertrain control module (PCM) will disable engine starting. Start disable may be in the form of fuel disable or starter disable, depending on engine application.
The components of the Passlock?"¢ System are as follows:
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The ignition lock cylinder and key

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The ignition lock cylinder case, including the Passlock?"¢ sensor

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The ignition switch

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The body control module (BCM)

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The security indicator on the instrument cluster

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The powertrain control module (PCM)

The body control module (BCM) contains the logic of the Theft Deterrent System. The BCM provides the battery positive voltage to operate the Passlock?"¢ sensor. The BCM also measures the voltage of the security sensor signal circuit. The voltage measured will indicate whether the Passlock?"¢ sensor has been activated and whether the resistance value from the sensor is a valid value or the tamper value. If voltage measured is in the valid range, the BCM compares this voltage, voltage code, to a previously learned voltage code. If the voltage codes match, the BCM sends a class 2 message containing a password to the powertrain control module (PCM). If the voltage codes do not match, or the voltage is in the tamper range, or there is a circuit fault, the BCM will not send the correct password to the PCM, and the vehicle will not start.
The body control system consists of a BCM and it's associated controls. Battery positive voltage is provided to the BCM from CLSTR fuse in the Fuse Block-left I/P. The module ground is wired to ground G201. The BCM is wired to the Class 2 serial data communication bus as well as discreet input and output terminals to control the functions of the vehicles body !
Now then Karen what problem is your vehicle having , no start an SECURITY light flashing or on solid ?
Now then

No where in the DTC - description does it say anything about replacing any modules . An does not have anything to do with a communication problem ! You need a professional grade scan tool to communicate with the PATS system ! An if you don't know these thing's you better take it to pro !!!!!!!
P1260 - Theft Detected - Vehicle Immobilized Indicates that the passive anti-theft system (PATS) has determined a theft condition existed and the engine is disabled. This DTC is a good indicator to check the PATS for DTCs.

• Previous theft condition
• Anti-Theft System failure

Theft indicator flashing rapidly or on solid when ignition switch is in the ON position. Check anti-theft system for DTCs. Typical vehicle symptoms are: Start/Stall or Crank/No Start. NOTE: No crank symptom only on vehicles equipped with PATS starter disable feature

The problem you are experiencing is the security anti theft system. It will literally shut off you starter or injectors to prevent theft (or when it fails, like in your situation) You can bypass this feature and leave your existing ignition as is.

http://vatspasslockpasskeysecurityhelp.yolasite.com/

If you disable your alarm system because of embarrassment ( a poor excuse for too lazy to fix) imagine your inconvenience when someone steals the vehicle because you didn't hear it go . IT may be a simple thing such as resetting the CPU with a code reader or going to a good auto electrician or chevy service centre to have it fixed

Anti-theft system has nothing to do with it . Battery cables , maybe , Park neutral safety switch possibly ! With anti-theft system problem you wouldn't a click or anything , that is if the anti-theft disables fuel or the starter . Plus the SECURITY light would be on if it were a anti-theft system problem . Your best bet , take it to a qualified repair shop that knows how to do starter circuit testing >
Starter Voltage Drop
How to voltage drop test starter motor circuit

And what's this identity anti theft system ? No such thing ! The vehicle has a content theft an vehicle theft deterrent system !
This system disables fuel not cranking of the engine. The VCM/PCM will not disable the fuel due to any BCM message for the remainder of the ignition cycle.
If the VCM/PCM does not receive the same password from the BCM as the last learned one, the vehicle will start and then stalls due to the Fuel Lockout.

You say it has fuel pressure, if it has sequential fuel injection it needs about 70psi to start the engine.
If it cranks and has spark to the plugs, the anti-theft system is not involved.
You did not mention the rotor, I assume you have spark to the plugs not just out of the coil.
If you have not yet checked cranking fuel pressure, I would start there. The pump could be weak or the filter stopped up.

This is most likely the Anti Theft Security system shutting down the starter. Gm vehicles have had this problem since the 80's. Your key is not just a key, it also has a chip in the shaft or a transponder in the head. This Communicates with the ignition/ lock cylinder. This then communicates with the TDM (Theft Deterrent Module) which then ALLOWS the ignition to start the vehicle. Any communication break, and the vehicle wont start at the key/ignition. Check out this link for some more info and "do it yourself" solutions http://vatspasslockpasskeysecurityhelp.yolasite.com/

Just on a hunch, it could be the Anti theft security causing the "no start". This is pretty common on GM vehicles. Read up on it thru this link. It lists some symptoms and "do it yourself" solutions if this ends up being your problem. http://vatspasslockpasskeysecurityhelp.yolasite.com/