If you have a stubborn or recurring problem of the sliding door power
lock not working, clean the contacts thoroughly with 1500-grit
sandpaper.  If that doesn't work, carefully file down the wear
grooves in the spring-loaded contacts so they're at least mostly
gone.  That makes sure the contact is on the little raised dots on
the door connector, which are the only part you can keep bright and shiny.

Yours,
David