Place brisket in a large slow cooker. In a small bowl, combine chili sauce, cola, and soup mix, then drizzle over the brisket. Cover.
2.
Cook on LOW for 6 to 7 hours. Remove meat from slow cooker and place on a plate; cover with foil. Remove any extra fat floating in the pan juices, then pour juices into a saucepan.
3.
Bring pan juices to a boil over medium heat. Whisk the cornstarch and water together in a small bowl, then slowly add to saucepan with pan juices. Cook for 2 minutes or until sauce is thickened.