One problem related to automatic transmission column shift has been reported for the 2003 Chevrolet Silverado. The most recently reported issues are listed below.
Upon parking, had slight difficulty placing vehicle into park gear position on very slight incline in driveway of home. Stepped out of vehicle, returned a few minutes later to find vehicle had rolled into pole. Attempted to start vehicle, but would not start, tried to put vehicle in neutral, and column shift was very loose. Applied parking brake and contacted dealer for tow next morning. Dealership determined the shift cable had broken, replaced with new shift cable. Only explanation offered was plastic sheath had cracked allowing cable to kink, they stated initially it sometimes happens, but they did not explain why. I am very concerned that if vehicle were parked on street on a slight grade it would have rolled downhill possible causing damage or injuring someone.