New Holland CX720 Repair Manual page 1876

POWER PRODUCTION - FUEL AND INJECTION SYSTEM
When the key is first turned on, power from the key switch S-02 pin 5 travels through the wire harnesses to the ECU
connector X193, pin 15, signaling the ECU to "wake-up". The ECU then connects the ground path for the coil of the
ECU Power relay K-14, causing the relay to energize and provide main power for the ECU at connector X193, pins 3
& 4, as well as for the grid heater relay K-39.
If the operator turns the key off, this cuts off the power supply to the ECU connector X193, pin 15. When this power
supply is lost, the ECU starts its "shut down" routine, including saving files and operating information to memory, and
shuts down the engine fuelling system to stop the engine. After several seconds, the ECU disconnects the ground
path for the ECU Power relay K-14 coil, and the relay unlatches, stopping main power supply to the ECU.
Engine shutdown in the event of machine problems, or for an operator-signaled "kill-stall", is handled by sending a
message to the ECU through CAN, and the ECU shuts down the engine without powering itself off in the process.
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