One problem related to manual transmission column shift has been reported for the 2003 GMC Yukon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 GMC Yukon based on all problems reported for the 2003 Yukon.
When the vehicle's ignition is in the accessory position the transmission can be shifted into reverse, neutral, drive, etc. Without the brake pedal being pressed. My 3 year old was sitting in my lap in the drivers seat in a parking lot listening to the radio in accessory mode he pulled the gear selector down into neutral and the car began to roll. Thinking that this was not possible, I took the vehicle into the dealership. Their reply, "OH that's weird, I didn't know it would do that". No fix, just, "we will look into it".