An integrated automated idle reduction system is disclosed. The system may include an APU and various controllers providing automation. The system may enable automating features, such as automatically controlling various power sources, engine start, engine stop, the APU, and accessory systems. The APU may be an engine, battery and/or other power source that is selectably connectable to vehicle systems to provide electrical power while the OEM engine of the vehicle is not running. The APU may also provide electrical power while the OEM engine is not running. Additionally, the APU may drive an air conditioning compressor while the OEM engine is not running, such as to keep the cab of a vehicle cool. Prior cold starting the OEM engine, the APU may warm engine coolant, and the integrated automated idle reduction system may circulate the warmed coolant through the OEM engine in preparation for starting.