2006 Chevrolet Colorado Owner's Manual - Page 204

Theft-Deterrent Feature (Non-RDS Radios) THEFTLOCK is designed to discourage theft of your vehicle's radio. The feature works automatically by learning a portion of the Vehicle Identification Number (VIN). If the radio is moved to a different vehicle, it will not operate and LOC will appear on the display. With THEFTLOCK® activated, the radio will not operate if stolen. ® Radio Reception You may experience frequency interference and static during normal radio reception if items such as cellphone chargers, vehicle convenience accessories, and external electronic devices are plugged into the accessory power outlet. If there is interference or static, unplug the item from the accessory power outlet. AM The range for most AM stations is greater than for FM, especially at night. The longer range can cause station frequencies to interfere with each other. For better radio reception, most AM radio stations will boost the power levels during the day, and then reduce these levels during the night. Static can also occur when things like storms and power lines interfere with radio reception. When this happens, try reducing the treble on your radio. Theft-Deterrent Feature (RDS Radios) THEFTLOCK® is designed to discourage theft of your vehicle's radio. The feature works automatically by learning a portion of the Vehicle Identification Number (VIN). If the radio is moved to a different vehicle, it will not operate and LOCKED will appear on the display. When the radio and vehicle are turned off, the blinking red light indicates that THEFTLOCK® is armed. With THEFTLOCK® activated, the radio will not operate if stolen. 3-74