Will not start theft light flashing? - 2004 Ford Mustang

Your vehicle has two theft systems - content theft , if the door is opened without the key or keyless entry key fob the horn honks lights flash . PATS - passive anti-theft system ,this keeps the vehicle from starting if the computers don't see the right code from the transponder pellet in the head of the key .
You can turn off the content theft but not the PATS , when trying to start the vehicle does the theft light flash fast ? Red light on top of the dash .

The Anti Theft light is programmed to operate four different ways. A slow flash is visible while the engine is off. This is an added theft deterrent and is by design. With the key in the run position (not running) the Light will function three different ways. A "Fast Flash" will alert you of an active fault and "Solid Light" indicates a stored fault. Both faults will disable the starting system. Lastly a "Slow three Flash, then the lights turns off" indicates the system is operating normal. More than likely the issue will be at the ignition key but diagnostics is needed. Any questions please write back. Good Luck.

I have had the same problem. This has happened to me three times in the past nine months or so. Per the owner's manual, you turn the key to the on position and wait about ten minutes. This resets the system and when the "Theft System" light goes out, it starts right up. I did this each time and it started right up.

relearn of key less entry is done by crank engine slightly, leave key on until theft light quits flashing. turn key off then try to start. if no start and light is still flashing, anti theft sensor in key tumbler or body module fault..

Try turn key on car but not start for few min.Call dealer for alarms ask ththem.Or get online.

Thanks Ed

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The theft indicator on the instrument cluster will operate as follows:
• When the ignition is OFF, the theft indicator will flash briefly every two seconds to indicate the SecuriLock system is protecting your vehicle.
• When the ignition is turned to ON or START, the theft indicator will light for three seconds and then go out. If the theft indicator stays on for an extended period of time or flashes rapidly, have the system serviced by your dealership or a qualified technician.

Hope helps.

check to see if the security light or anti theft light flashes. if that is the case, sounds like the bypass for the remote starter may be causeing the no start by tripping the anti theft system. Remove remote starter and bypass system and join any cut wires back together that may be cut for remote starter. Try starting, if theft light still flashes leave key in the on position after attempted start for 15 minutes till theft light goes solid, turn off and try again. Repeat process for three times to re-learn factory theft system in vehicle. If problem still persists, then take to your local dealer to reprogram factory theft module in the cluster.

If the security or anti-theft light is flashing when you attempt to start your car, and the engine does not crank or does not start, you have an anti-theft problem. The system may not be recognizing your key's key-less entry signal, or there may be a fault in the anti-theft module or wiring.
There is a reset procedure to stop this anti-theft light flashing.many a times this helps The reset procedure is as follows:-- Reset the alarm by locking and unlocking the drivers side door.Do this a couple of times and then check it will reset the factory security system . If the reset procedure does not helps then its time to get the anti-theft system checked.There is a short circuit in the anti-theft system wiring. For more detailed help on this anti-theft light blinking issues please click on the link below http://www.aa1car.com/library/troubleshoot_antitheft_system.htm
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I just had this same thing happen with my Ford Taurus, and it turned out to be a bad key. The repair shop switched back and forth between two different keys we had with us 10 or 12 times, and it always started with the good key, never with the "bad" key. They said if the theft light is flashing quickly, that means the anti-theft system is engaging. If the anti-theft light just lights up, that is normal.