l locked my trunk from inside my car and now l can not get it to unlock. l read the manual and it said to use the master key and l did but the key want turn. What is the problem?

maybe you can try the trunk release? Most newer cars have one.

l would take it to the dealer or ask them about it. Any Honda dealership.

the master key is the black key' the valet key is the grey one & the valet key wo not unlock the latch.

the first thing l recommend is using a toothpick to open the slot where the key goes then use a vacuum cleaner to try to suck out any dirt or debris that may have gotten wedged in there when it was locked.

then spray WD40 into the slot for the key. then try the master key. also, u may want to pull up slightly on the lever as you're turning the key or push down on the lever as u turn the key to take the pressure off the lock cams.

if none of that works then the only option is to go to the dealer. if the car is under 3 years or 36,000 miles you're still in the factory warranty & it should be covered

hope that helps