When a GM radio displays the "LOC" this means the Theft Lock has been activated on the vehicle. The only way to get it to work after this occurs is to unlock the radio. The process for unlocking the radio is one that can be done by the dealer,but it can also be done by the car's owner in the driveway at home. So instead of driving to the dealer and paying someoneto unlock the radio, follow this short process and save some money.
Turn the ignition key to the "on" position. It may be necessary on some vehicles to start the vehicle. Most will not require the vehicle to be running.
1.Press and hold the preset buttons numbered two and three for 10 seconds at most. Write down the three-digit number that displays on the screen. Some radios will display only two digits.
2.Press the "AM/FM" button on the radio. Write down the second three-digit number. Again, some radios will only displaytwo digits. The AM/FM button has to be pressed quickly after getting the first code. If pressing the button does nothing,then start over.
3.Call 1-800-537-5140 and listen for the make of the vehicle: Chevrolet will be one, Oldsmobile will be two and so on.
4.Press the number corresponding to the make of the vehicle followed by 06010 then the "*" or star key. So for aChevrolet radio, for instance, the number entered will be 106010*.
5.Enter the four- or six-digit code retrieved from the radio. Then write down the code given over the phone.
6.Go back to the radio and press the "Hour Set" button until the first two digits of the code from the phone appear. Now press the "Minute Set" button until the second two digits of the code appear.
7.Press the "AM/FM" button. The word "SEC" should appear on the screen. If it does then turn the radio on and it will work. If not then repeat steps 4 through 7 and get additional codes.