I have a 2007 cadillac cts and the check antI theft system light is on car will start no gages working key will not come out. What could be causing this problem.

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By disconnecting the battery, you also disconnected all the set up of the security and engine immobilizer coding.

https://www.google.com/search?q=2003+cadillac+cts+security+system+reset

How do i perform the 2003 Cadillac CTS anti theft reset?

Vehicle History https://www.vehiclehistory.com > questions > how-do-...
To reset the anti-theft system in your 2003 cadillac cts depress the key fob's panic button for five seconds before pressing the lock button twice standing ...
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How do I get my Cadillac out of anti-theft mode?"

Look for a button that allows you to slide the physical key out of the fob. Step 2: Turn the vehicle key to unlock the car door without releasing it. Hold the key for 30 seconds in this position. This will signal to your car's system that you have the right key, and will enable you to bypass your car's alarm system.

Visit the on-line store, know as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem.
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If your theft light is on and stays on after the key is in the on position after self check, then you will most definitely have a no start condition. You can try leaving the key on for about 15 minutes to see if the theft system will reset. If so, you will probably need to have the lock cylinder and halo replaced.

Is the security light lit ? Car an pad lock symbol . If any of these are lit it is the anti-theft system . Does the engine crank over but won't start an run ? The anti-theft system will allow the engine to crank but not start , disables fuel injectors . If the anti-theft light is lit there are DTC'S diagnostic trouble codes stored in the theft deterrent module an or the ECM .
Does anything happen when you turn the key to the start position ?

use a scan tool to reset the ECM

there is one wyre you can cut coming from the computer check itrenet taht will disable antitheft everything else will work properly that will let you no if it is the anti theft

Have your dealer or a qualified Cadillac mechanic check the anti-theft system and your key. Your ECM may need to be re-flashed, but have a diagnostic scan performed to determine possible solutions.

sounds like anti theft device has kicked in needs to be reset dont know how to do that though

Don't do that again! You will need to re-boot the on board computer system by entering a code. Call your nearest Cadillac dealer.

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