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How to Disable Chevy Theftlock

by Andy Pasquesi

The Theftlock Sound System was designed by General Motors (GM) to discourage criminals from breaking into vehicles to stealing radios and is used in many of the company's automobiles, including Chevrolet models. However, if the 4-digit password gets lost, the system becomes inaccessible, effectively taking CDs hostage. Luckily, GM has provided a convenient (and safeguarded) protocol for recovering lost passwords.


Put the key in the ignition and turn it to the "On" position. You don't have to start the engine, just turn on the car's electrical system. If the radio's digital display reads "INOP," leave the electrical system on for one hour before proceeding to the next step. If the display reads "LOC," proceed to Step 2.


Press and hold radio preset buttons 2 and 3 for six seconds. This will cause the radio's digital display to change from "LOC" to a random three-digit number.


Write this number down quickly and press the AM/FM button (within a 15 seconds). If done correctly, this will cause a new three-digit number to appear.


Write down this second number.


Turn the car's ignition off.


Call 1-800-537-5140.


When prompted for a code, press "1" and "#". The automated operator will say, "Invalid Code. Try Again." But don't worry: this is merely a security measure.


Press "139010" followed by "#" on your keypad. The automated operator will then ask you to enter your 4- or 6-digit code.


Enter the three-digit number from Step 3 followed by the three-digit number from Step 4. Press "*". The automated operator will then read a 4-digit code back to you, twice.


Write down this 4-digit code.


Turn the key in the ignition. Again, just turn on the electrical system, not the engine.


Press the "HR" (hour) button on the radio to set the clock's hour to the first two digits from the 4-digit code. For example, if the code was 0359, you would set the hour to 03 or three o'clock.


Press the "MN" (minute) button on the radio to set the clock's minutes to the last two digits from the 4-digit code. Using the example of 0359 from above, you would set the minutes to 59.


Press the AM/FM button. If done correctly, the digital readout should say "SEC".

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About the Author

A Chicago-based copywriter, Andy Pasquesi has extensive experience writing for automotive (BMW, MINI Cooper, Harley-Davidson), financial services (Ivy Funds, William Blair, T. Rowe Price, CME Group), healthcare (Abbott) and consumer goods (Sony, Motorola, Knoll) clients. He holds a Bachelor of Arts in English from Harvard University but does not care for the Oxford comma.

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