Shifting Problem......... on 1999 GMC Yukon

My shift is stuck in "Park"! My neighbor had a Theory;short out the two wires,connected to column from the brake and/or safety mechanism.....It worked! But,when;I tried the same thing,NOTHING! I Noticed;that,the signals were OUT(due to shorting the wires). How can I correct this Problem

Asked by for the 1999 GMC Yukon
Do your brake lights work? The brake switch needs to work so it can trigger the solenoid to release the Shift Lever. Good Luck!