Using a brush, baste the tenderloin with the honey.
Combine the garlic, ½ cup bbq sauce, brown sugar, and black pepper together in a small bowl. Mix well.
Using a brush, baste the tenderloin with the sugar and bbq mixture.
Place the lid and cook on high for 3-4 hours or on low for 5-6 hours. The internal temperature should read 145 degrees. Check early so it's not dried out! Add additional cooking time of needed.
Add the remaining BBQ sauce within 15 minutes of removing the pork tenderloin from the Crockpot. *optional for a greater BBQ flavor, brush with an additional ¼ cup of bbq sauce.
Remove the tenderloin from the crockpot and allow it to rest for 10 minutes before slicing and serving.