Truck starts on its own

toedtoes wrote:
Found a thread with this quoted from a 2020 model manuel:

"AFTER-RUN SYSTEM (HD Model)

HD models are equipped with an engine cooling feature that may be required to run after a heavy towing event. The After-Run System will keep the engine running, or may restart the engine, for 10–15 minutes to ensure the engine and related components are properly cooled. See Driving and Operating in your Duramax Diesel Manual."

And

Intended Vehicle Use: After a Heavy Towing Event
If equipped, when the vehicle is turned off after towing heavy loads, the system may automatically restart the engine. A chime will sound and DIC messages will display. The engine will automatically turn off after 10–15 minutes of run time or if enough cooling has occurred.
If the DIC messages display after the vehicle has been stopped and placed in P (Park) with the engine still running, remain in the vehicle with the engine running until these messages no longer display. It may take up to 15 minutes of idling. Do not park the vehicle in an enclosed area if the messages display.
If the system determines that the engine should be restarted and the ignition is turned off, the engine will turn off and then automatically restart. If the engine is restarted, DIC messages display and chimes will sound. The vehicle cannot be shifted out of P (Park) unless the feature is overridden.
Never leave occupants in the vehicle, and always take the keys and lock the doors if you must leave the vehicle idling. Some local laws prohibit a vehicle from idling unattended. Always remain with the vehicle until it automatically turns off. This could take up to 15 minutes.
If the system determines that the vehicle was not allowed to restart, or if a condition such as an open hood has been detected, then DIC messages display and a chime will sound. To help with system performance, either restart the engine, or if the engine is not running and the hood can be safely opened after one minute, open the hood to allow cooling.
If the system has automatically restarted the engine, the vehicle cannot move until cooling has completed and the engine automatically turns off. Overriding this feature will allow normal vehicle operation. To override, start the vehicle as you would normally. Then either drive the vehicle as normal or turn off the ignition if you must exit the vehicle. Opening the hood will prevent the restart or will turn the engine off when this feature is active.