Disconnected battery on my 2004 Saturn Ion to replace the starter and activated the radio theft deterrent feature. Pressed radio button 1 and 2 and the code 2566 appeared. I called my local GM dealer and naturally they were unwilling to provide me any assistance in getting the factory unlock code unless I paid them $60. Sounds like a scam since I had a similar problem with an Acura I own and they provided me the unlock code over the phone without a fee. I guess General Motors really isn't interested in assisting their customers unless they can soak some money out of them. Anyhow, any suggestions on how to obtain the factory unlock code without paying G.M.'s ransom?

Showing on what screen ?
Theftlock
Radio
The Theftlock theft deterrent system is a feature on all base and uplevel radios. There is no need to program a security code into the radio as in past model years. The theft deterrent system now utilizes GMLAN to determine if the radio is in the appropriate vehicle. Each time the radio receives the "run" power mode message, it compares the VIN information it has stored to the VIN information received from the instrument panel module (IPM) on the GMLAN circuit. If a mis-match occurs, the radio display will indicate to the user the radio is locked. Once this takes place, a DTC will set, the radio will not respond to any button presses and become inoperative. The two scenarios able to cause this condition are:
A radio is installed from another vehicle
The IPM is replaced and not properly setup with the correct VIN information for that vehicle
The only way to unlock the radio is by using a scan tool. Always refer to the table in this section to diagnose the Theftlock DTC for further information.

Your SECURITY light lit on the instrument cluster ? or you disconnected the battery an now the radio is locked ?
The theft deterrent system on this vehicle is comprised of the vehicle theft deterrent (VTD) system. VTD prevents drive away theft by preventing the vehicle from starting.
SECURITY Indicator The SECURITY indicator on the instrument cluster is controlled by the VTD system. The SECURITY indicator is located inside the instrument cluster. The SECURITY indicator is controlled by the body control module through the class 2 data line. The VTD system contained in the BCM commands the instrument cluster to control the SECURITY indicator only when the ignition switch is ON. The VTD system uses the indicator as a malfunction indicator.
Theft Deterrent
The "Theftlock" theft deterrent system is a feature on all base and uplevel radios. There is no need to program a security code into the radio as in past model years. The theft deterrent system now utilizes class 2 serial data to determine if the radio is in the appropriate vehicle. Each time the radio receives the "run" power mode message, it compares the VIN information it has stored to the VIN information received from a module on the class 2 serial data circuit responsible for transmitting that information. If a mis-match occurs, the radio display will indicate to the user the radio is locked. Once this takes place, a DTC will set, the radio will not respond to any button presses and become inoperative. The two scenarios able to cause this condition are:
?€¢
A radio is installed from another vehicle.

?€¢
A module which communicates on the class 2 serial data circuit which supplies VIN information to the radio is replaced and not properly setup with the correct VIN information for that vehicle.

The only way to unlock the radio is by using a scan tool. Always refer to the table in this section to diagnose the "Theftlock" DTC for further information.
So what problem are you having ?

Here's some info as it sound like the theft deterrent is armed.

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Reset Procedure

NOTE: This information applies to a Vehicle Theft Security System (VTSS) that was armed when the battery was disconnected and reconnected.

When the armed VTSS senses that the battery has been disconnected and reconnected, it enters its power-up mode. In the power-up mode the alarm system remains armed following a battery failure or disconnect. If the VTSS was armed prior to a battery disconnect or failure, the system will have to be actively or passively disarmed following a battery reconnection.

The power-up mode will also apply if the battery goes dead while the system is armed and battery jump-starting is attempted. The engine no-run feature will prevent the engine from starting until the alarm system has been actively or passively disarmed.

Passive disarming of the Vehicle Theft Security System (VTSS) occurs when the vehicle is unlocked using the key to unlock either front door or the liftgate. Active disarming of the VTSS occurs when the vehicle is unlocked by depressing the Unlock button of the Remote Keyless Entry (RKE) transmitter.

Once the alarm has been activated (horn sounding, lights flashing, and the engine no-run feature), either disarming method will deactivate the alarm.

Depressing the Panic button (if equipped) on the RKE transmitter will also disarm the VTSS, but the horn will sound and the lights will flash for about three minutes as part of the Panic feature. The horn and lights can be stopped by pressing any of the RKE transmitter's buttons or driving the vehicle above 15 mph.

Yes, just in case you have a theft deterrent system, do not leave the battery cable disconnected longer than 30 minutes as that will cause your radio to loose its smarts and not be able to turn on.

the anti theft wire under the steering column gets to cold and locks out ignition. i just found the auto theft wire and disconnected it. or you can take a blow dryer or heat gun run under the steering column for 3-5 minutes. if you do disconnect the auto theft wire you must do it while the car is running. use the blow dryer method, start the car then disconnect the auto theft wire.

This sounds like the theft deterrent feature is activated..take a look at the security light when this happens..is it flashing?? if so try a different key or you may have to replace the Ignition cylender and relearn the theft deterrent system...only done at a shop or someone that knows what their doing..

The "Theftlock" theft deterrent system is a feature on all base and uplevel radios. There is no need to
program a security code into the radio as in past model years. The theft deterrent system now utilizes
class 2 serial data to determine if the radio is in the appropriate vehicle. Each time the radio receives
the "run" power mode message, it compares the VIN information it has stored to the VIN information
received from a module on the class 2 serial data circuit responsible for transmitting that information.
If a mis-match occurs, the radio display will indicate to the user the radio is locked. Once this takes
place, a DTC will set, the radio will not respond to any button presses and become inoperative. The
two scenarios able to cause this condition are:

• A radio is installed from another vehicle.
• A module which communicates on the class 2 serial data circuit which supplies VIN information to the radio is replaced and not properly setup with the correct VIN information for that vehicle.
  

SOURCE: MITCHELL1

I am surprised the dealer wont do this for free,especially when you say it's a Saturn.Go to your local audio shops see if they can help instead of the dealer,you will be surprised what they know.

you have activated the theft deterrent feature of your radio, u will need the code that came with the owners packet when the car was sold, if u don't have that u will need to pull the radio out and get the model and serial number off the radio and go to the dealer who can supply this unique code for your car from the Honda data base on your car when it was sold.