SWITCH AS- 5284105 - Caterpillar

Engine
Check the engine crankcase oil level. Maintain the oil level between the "ADD" and "FULL" marks on the "ENGINE STOPPED" side of the oil level gauge.
If necessary, perform minor adjustments. Repair any leaks and tighten loose bolts.
Note the service hour meter reading. Perform the maintenance that is scheduled in this Operation and Maintenance Manual, "Maintenance Interval Schedule" (Maintenance Section).
Follow the guidelines for antifreeze/coolant mixtures that are recommended in this Operation and Maintenance Manual, "Refill Capacities and Recommendations" topic. Failure to do so can cause engine damage.
Allow the engine to cool. Check the coolant level.
Loosen the cooling system filler cap slowly to relieve any pressure. Remove the cooling system filler cap.
If freezing temperatures are expected, check the coolant for protection against freezing. The cooling system must be protected against freezing to the lowest expected outside temperature. Add the proper coolant/water mixture, if necessary.
Perform all required periodic maintenance on all driven equipment. Refer to the instructions that are provided by the OEM of the driven equipment.Aftertreatment Purge Cycle
Note: Air supply must remain active while the system purges.Under certain conditions the aftertreatment control system will run the DEF dosing system through a DEF purging cycle. This purge cycle will drain the DEF line between the dosing cabinet and the DEF injector. The purge cycle is designed to protect the DEF system, and to prevent the DEF from freezing. The purge cycle also protects engine exhaust hardware from DEF leaking from the DEF injector. The system will enter purge mode when the engine speed has dropped below a set threshold. The system will also enter a purge cycle if certain codes are logged during operation.During purge cycle, the DEF return valve on the DEF manifold will open and the dosing pump is turned off. The purge cycle will allow the air pressure in the line to force remaining DEF in the nozzle/line back to the tank. The purge cycle is a time-based event. The event should take less than 2 to 3 minutes.Dosing air supply must remain pressurized with air available always during engine operation. This process is required to ensure that the urea dosing lance is adequately cooled.