HomeAll RepliesReply To: Active Fuel Management's impact on engine braking Reply To: Active Fuel Management's impact on engine braking Sponsored July 14, 2016 at 8:15 pm #133281 Alex LuftKeymaster Yup, that’s exactly how AFM works. And I should have thought of the solution to shifting to manual mode . That does, indeed, disable AFM. Cheers and have a great Colorado day as well 🙂 Alex Sponsored Subscribe to GM Authority For around-the-clock GM news coverage We'll send you one email per day with the latest GM news. It's totally free. First Name Last Name Email Address Subscribe via Email Leave this field empty if you're human: Sponsored