Dynamic Description - Electrical - Case IH AXIAL-FLOW 7230 Service Manual

Engine - Fuel injection system
Fuel injection system - Dynamic description - Electrical
The Pump Control Valve L-52 is one of the output devices associated with the fuel system. The solenoid controls the
supply oil that flows to the high pressure pump, by receiving a Pulse Width Modulation PWM signal from the Engine
Control Unit A-01.
Simplified Circuit Diagram
1
NHPE11CR00089AA
Figure 1
NOTE: Figure 1 is a simplified functional diagram of the Fuel High Pressure circuit.
At key-on, A-01 will receive key switched power from Key Switch S-02 and its ignition circuit is complete.
Prior to fuel system operation, the (normally open contact) Seat Switch S-02 must be closed and the (normally open
contact) Park Brake Switch S-28 must be in the ON position.
After starting the combine with the S-28 in the ON position, the A-01 monitors to fuel temperature, pressure, and the
amount of water in the fuel. The Water in Fuel Sensor B-59 detects if water is present in the fuel and reports to the
A-01. The Fuel Level Sensor R-01 monitors the fuel level in the fuel tank. As the fuel level rises or lowers the variable
resistance of the sensor changes and those changes are recorded the Combine Control Module2 CCM-2 and the
CCM-2 displays the appropriate level on the operator gauge and sends the level data to A-01, using the shared CAN
lines.
The main component of the fuel system is the volatility level and the fuel pressure and temperature dictates that level.
The Fuel Temperature Sensor B-36 and the Fuel Pressure Sensor B-67 monitors the temperature and pressure, then
reports any changes to A-01. The fuel temperature has to be maintain so the fuel can be easily vaporizes. And the
fuel pressure has to be high enough to atomizes the fuel. In the case when the fuel pressure is too low, the A-01 sends
an 12 V output signal to the L-52. The energized L-52 opens a path for the supply oil to flow to the high pressure
pump, to increase the fuel pressure for proper atomization.
The fuel system then routes the high pressure fuel to the fuel rail, where it is stored until the A-01 energizes one of
the engine's fuel injectors.
48040837 15/08/2017
10.3 [10.218] / 3