LINK 0050387 - Caterpillar

Stopping the engine immediately after it has been working under load can result in overheating and accelerated wear of engine components.Refer to the following procedure to allow the engine to cool and to prevent excessive temperatures in the turbocharger housing, which could cause oil coking problems.
Allow 2 minutes after engine shutdown to apply the battery disconnect switch. Applying the battery disconnect too soon will prevent the DEF system from being purged and could cause DEF to freeze in the lines.
While the machine is stopped, run the engine for 5 minutes at LOW IDLE.
Illustration 1 g03584119
Turn start switch key (1) to the OFF position. Remove the start switch key. Delayed Engine Shutdown
The Delayed Engine Shutdown allows the engine to run for a time after the engine start switch key is turned to the OFF position to cool the engine and system components. The engine start switch key may be removed.Note: The DEF purge process will run for 2 minutes once the engine is shut down and must complete. The purge process may occur during delayed engine shutdown. Do not turn off battery disconnect switch during the purge process. Do not turn off the battery power disconnect switch until the battery disconnect switch indicator lamp has turned off. If the purge process does not complete, a diagnostic code will become active.Note: There may be regulations that define the requirements for the operator and/or support personnel to be present when the engine is running.
Leaving the machine unattended when the engine is running may result in personal injury or death. Before leaving the machine operator station, neutralize the travel controls, lower the work tools to the ground and deactivate all work tools, and place the lever for the hydraulic lockout control in the LOCKED position.
Note: Leaving the engine unattended while running may result in property damage in the event of a malfunction.Delayed Engine Shutdown - The delayed engine shutdown indicator will illuminate or the following text will be displayed, ENGINE Shutdown Delayed, Do Not Override.Turn the engine start switch to the OFF position.Delayed engine shutdown will run whenever the exhaust temperature is above a threshold at engine shutdown. Delayed engine shutdown will run for a minimum of 76 seconds and will continue to run until the engine and system components are cooled. The default maximum run time is 7 minutes.Note: An authorized dealer can change the maximum run time value up to 30 minutes, but the default setting is 7 minutes.
Illustration 2 g03797801
DELAYED ENGINE SHUTDOWN OVERRIDE - Turn the engine key switch to the DELAYED ENGINE SHUTDOWN OVERRIDE position and hold the engine key switch in that position for 1 second to override delayed engine shutdown (DES). The engine will be shut down immediately.Note: Overriding delayed engine shutdown may reduce engine and system component life. A warning message and/or audible alarm will be initiated and a fault code will be logged for improper engine shutdown.Note: At any time during a delayed engine shutdown, the engine start switch may be turned to the ON position.