if your tailgate button doesnt work
If your tailgate button doesnt work This stems from the microswitch's rubber cover slipping out of its groove and jamming the switch.
To fix it raise the tailgate and you will see a rectangular rubber seal which you push to activate the trunk lock. Look at its perimeters and you will definitely find an area where it has sunk into the groove in which it is housed too far. Use your fingernail or a small pointed object and pry it out and reseat it properly.
In the future, just squeeze it gently, it will work just as well and avoid this problem.