My mother’s Toyota Avalon developed a problem overnight. it starts fine, but when you depress the button on the T-handle gear shift, it won’t move out of park. What could cause this?
The likely problem is with the shift interlock switch. There’s a little blocker of some kind that keeps you from pushing that button. It is moved out of the way by a little solenoid which activates after it gets a signal from the brake light switch that says the brakes are engaged.
If there is a problem with the brake light switch this will prevent you from being able to push the button. Then the problem could also be in the wiring between the brake switch and solenoid. Or the solenoid itself could be dead or gunked up and sticky.
Start by finding out whether or not the brake lights are coming on when you push the brake pedal.