At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.
If your lucky the dealer may still have it or the code may be written down at the back pages of your manual. The other place where you can get the code would be www.radio-code.com. before you try any of that, try 0000 to unlock your radio. Good luck and hope this helps.
HAVE YOU OWNED THE CAR SINCE IT WAS NEW? THE POWER HAS BEEN INTERRUPTED FROM THE STEREO. IT WILL TAKE A LOCK CODE TO UNLOCK IT. REFER TO YOUR OWNERS MANUL OR TAKE IT TO THE LOCAL GM DEALERSHIP.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
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.
If the clock will display for a few seconds that means it,(the clock) has power, and perhaps the entire unit. However, if the anti-theft is engaged, a dealer will be in your future. It will take them about a minute to un-lock the radio, or they will know if the radio no longer works.
There are 2 types of GM Theftlock, Theftlock I and Theftlock II. The
Theftlock I is found in pre 2000 vehicles, and Theftlock II is in the
later models.
Theftlock I - Uses a volatile user settable code that is input through
the key pad on the front of the Radio. If the power is lost (dead
battery etc.) the code is gone and must be re-entered for the radio to
work. But with the correct procedure the owner can unlock it.
Theftlock II - Uses an EPROM (erasable/programmable read only memory) or
a PROM (the difference is you can not alter the prom once it is
programmed).
In either case the code is burned in and holds even when the power is
lost. With Theftlock II the radio is married to the vehicle by way of
the VIN. When the vehicle is started the computer compares the number in
the radio with the VIN in the body control module. If they match, the
radio works, if not the radio displays LOC and you are finished, there
is no easy way around it. The radio will not work until you make a trip
to the dealer.
The dealer will use a TECH 2 scanner to change the VIN stored in the
radio. The radio does not need to be removed (for the serial number or
any other nonsense). The technician just plugs into the computer and
resets the VIN in the radio.
Thank you for using fixya, you can try removing the fuse to your radio for 5 min and reconnect it. This will reset the radio back to default and re-read the Vin number to the PCM to match with the radio. At most time this will get your radio working again and all you have to do is to re program the pre-set and clock.
There are 2 types of GM Theftlock, Theftlock I and Theftlock II. The Theftlock I is found in pre 2000 vehicles, and Theftlock II is in the later models.
Theftlock I - Uses a volatile user settable code that is input through the key pad on the front of the Radio. If the power is lost (dead battery etc.) the code is gone and must be re-entered for the radio to work. But with the correct procedure the owner can unlock it.
Theftlock II - Uses an EPROM (erasable/programmable read only memory) or a PROM (the difference is you can not alter the prom once it is programmed).
In either case the code is burned in and holds even when the power is lost. With Theftlock II the radio is married to the vehicle by way of the VIN. When the vehicle is started the computer compares the number in the radio with the VIN in the body control module. If they match, the radio works, if not the radio displays LOC and you are finished, there is no easy way around it. The radio will not work until you make a trip to the dealer.
The dealer will use a TECH 2 scanner to change the VIN stored in the radio. The radio does not need to be removed (for the serial number or any other nonsense). The technician just plugs into the computer and resets the VIN in the radio. Thank you for using Fixya and you may want to try pulling the fuse to your radio for 2 min and then reinstalling it. This may reset your radio and have the ECM recognize the radio matching VIN number to the Trailbalzer.
There are 2 types of GM Theftlock, Theftlock I and Theftlock II. The Theftlock I is found in pre 2000 vehicles, and Theftlock II is in the later models.
Theftlock I - Uses a volatile user settable code that is input through the key pad on the front of the Radio. If the power is lost (dead battery etc.) the code is gone and must be re-entered for the radio to work. But with the correct procedure the owner can unlock it.
Theftlock II - Uses an EPROM (erasable/programmable read only memory) or a PROM (the difference is you can not alter the prom once it is programmed).
In either case the code is burned in and holds even when the power is lost. With Theftlock II the radio is married to the vehicle by way of the VIN. When the vehicle is started the computer compares the number in the radio with the VIN in the body control module. If they match, the radio works, if not the radio displays LOC and you are finished, there is no easy way around it. The radio will not work until you make a trip to the dealer.
The dealer will use a TECH 2 scanner to change the VIN stored in the radio. The radio does not need to be removed (for the serial number or any other nonsense). The technician just plugs into the computer and resets the VIN in the radio. Thank you for using fixya and keep us posted.
There is no actual "security code" in the radio as in past model years. The newer theft deterrent system utilizes the class 2 serial data to determine if the radio is in the appropriate vehicle...in other words it compares the VIN it has stored in it's memory with the VIN of the other modules (body control and PCM) in the vehicle to "check" to see that it's in the correct 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 the radio will not respond to any buttons/commands and becomes inoperative. But the dealer can reestablish the radio into a different vehicle with a scanner. There are 2 types of GM Theftlock, Theftlock I and Theftlock II. The Theftlock I is found in pre 2000 vehicles, and Theftlock II is in the later models.
Theftlock I - Uses a volatile user settable code that is input through the key pad on the front of the Radio. If the power is lost (dead battery etc.) the code is gone and must be re-entered for the radio to work. But with the correct procedure the owner can unlock it.
Theftlock II - Uses an EPROM (erasable/programmable read only memory) or a PROM (the difference is you can not alter the prom once it is programmed).
In either case the code is burned in and holds even when the power is lost. With Theftlock II the radio is married to the vehicle by way of the VIN. When the vehicle is started the computer compares the number in the radio with the VIN in the body control module. If they match, the radio works, if not the radio displays LOC and you are finished, there is no easy way around it. The radio will not work until you make a trip to the dealer.
The dealer will use a TECH 2 scanner to change the VIN stored in the radio. The radio does not need to be removed (for the serial number or any other nonsense). The technician just plugs into the computer and resets the VIN in the radio. Thank you for using fixya and good luck. you might get luck by removing the fuse toy our radio for 5 min and reinstalling it, this will reset the radio to default and all you need to do is reset the clock and radio presets.
thats because its a key code security device once you disconnect its power source the radio will automatically lock itself to prevent theft but you can take it to a shop that sells radios and they can reset it for you but its impossible to diy because you need a computer to programme the microchip so take it to a shop m8 otherwise it wont work mine did the same hope i helped :)
Press & hold the 2 & 3 buttons at the same time for about 10 seconds; a 2 or 3 digit code will appear, write this # down, press & hold the am/fm button for about 10 seconds: another code will appear, write this # down, then call 1-800-537-5140 and enter 202108 (this is a dealer code - you can use one of the others below, too) followed by the # key, then enter the numbers that you wrote down, followed by the * key. The call will give you a 3 or 4 digit override code. Write this code down so you have it if you ever need it again. Enter this number into your radio following the instructions in your owners manual.
Note: If you get an override code that starts with 0, you drop the 0 when entering the code into your radio.
If you don't have an owners manual, then press & hold the hour button until the first 2 digits of your code come up, then press & hold the minute button until the last 2 digits show. Then press the am/fm button. Repeat step #5 twice in a row it will disable the Theftlock and you will see "---". You will then be able to change to a new lock code.
IMPORTANT - Other dealer codes: 139010, 206053 and 620529 - these may be inactive by now; GM will remove them from time to time if they feel that they are "compromised".
Also - there are 2 modes to the TheftLock - "LOC" or "SEC" and "INOP". Once the anti-theft is activated, the radio display will show "LOC" or "SEC" - you then have 8 attempts to enter your code. If after 8 attempts you don't enter the correct code, the display will change to "INOP". It is only at this time that you will need to wait one hour, with the ignition ON; before you can retry. After that - you will have only 3 attempts before the radio enters "INOP" mode again.
×