1.Carry the smart key or place it inside the vehicle.
2.Make sure the parking brake is firmly applied
3.Place the shift lever in P (Park). Depress the brake pedal fully. You can also start the engine when the shift lever is in the N (Neutral) position.
4.Press the engine start/stop button while depressing the brake pedal.
5.Do not wait for the engine to warm up while the vehicle remains stationary. Start driving at moderate engine speeds. (Steep accelerating and decelerating should be avoided.)
WARNING - Unintended vehicle movement
Never leave the smart key in the vehicle with children or vehicle occupants who are unfamiliar with the vehicle operation. Pushing the engine start/stop button while the smart key is in the vehicle may result in unintended engine activation and/or unintended vehicle movement.

Do not press the ENGINE START/ STOP button for more than 10 seconds except when the stop lamp fuse is blown.
Kia Stinger (CK) 2018-2023 Owner's Manual: Transmission Control Module (TCM)
Components and components location Components Location 1. Transmission Control Module (TCM) Description and operation Description The module receives and processes signals from various sensors and implements a wide range of transmission controls to ensure optimal driving conditions for the driver.Description and operation Description The ISG OFF switch on the floor console can be used to deactivate the ISG function. Repair procedures Removal Put on gloves to protect your hands. • When prying with a flat-tip screwdriver or use a prying trim tool, wrap it with protective tape, and apply protective tape around the related parts, to prevent damage.