2003 Tundra doors unlock while driving

My 2003 Tundra access cab has reached 90,000 miles. I brought it into the auto shop for its first timing belt, waterpump replacement service. On the way home from the shop, the doors unlocked, so I relocked them. I pressed the A/C button and they unlocked again. Never happened before I took it in. Did the shop forget something? Maybe a ground wire or relay? Any help would be appreciated. Thanks.