FRAME GP-REPAIR 3913097 - Caterpillar

Inputs
The inputs describe the status of the machine systems. Two types of inputs exist. The inputs can be either a switch type or a sensor type. Switches provide an open, a ground, or a + battery signal to the inputs of the controller. Sensors (frequency, PWM, or voltage) provide a changing signal to the sensor inputs of the controller. The controller will recognize the following types of sensor signals:Frequency - The sensor will produce an AC signal (sine wave or square wave) that varies in frequency (Hz) as the condition changes.Pulse Width Modulated - The sensor produces a digital signal and varies the duty cycle as the condition changes. The frequency of the signal will remain constant.In some cases the operator is provided a manual switch that can be used to change a condition of the machine.Sensors
Low Pressure Sensors
Illustration 3 g02263393Note: The values in Table 3 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 3
Operating pressure 10 MPa
Supply Voltage +7V ~ +14V
Output signal 500 100 Hz (PWM)
Output range 5% ~ 95% Negative Flow Control Pressure Sensors
The negative flow control pressure sensors for the drive pump and idler pump are inputs to the machine ECM. The machine ECM uses this pressure information to determine the hydraulic demand requested by the operator. The machine ECM then sends a PWM driver to the negative flow control solenoids to control the pump flow rate.The NFC pressure sensors are located on the top on the main control valve in the end plate.For more information on the NFC pressure sensors, refer to Systems Operation, "Negative Flow Control System".High Pressure Sensors
Illustration 4 g02263513Note: The values in Table 4 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 4
Operating Pressure 50 MPa
Supply Voltage +7V ~ +14V
Output Signal 500 100 Hz (PWM)
Output Range 5% ~ 95% Drive Pump Pressure Sensor and Idler Pump Pressure Sensor
The drive pump pressure sensor and idler pump pressure sensors are inputs to the machine ECM. The drive pump and idler pump pressure sensors are located on the main control valve. The drive pump pressure sensor monitors the pressure of the drive pump oil in the front half of the main control valve high-pressure passages. The idler pump pressure sensor monitors the idler pump oil pressure in the rear half of the main control valve high-pressure passages.The pressure sensors send a pulse width modulated (PWM) input to the machine ECM. This pressure information is used for pump control and travel speed.Outputs
The ECM responds to decisions by sending electrical signals to the outputs. The outputs can create an action or the outputs can provide information to the operator or the service technician.Proportional Reducing Solenoid Valve
Illustration 5 g02703776Note: The values in Table 5 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 5
Current Range 0 mA ~ 700 mA
Coil Resistance 15.0 0.7Ω (T=20° C) Power Shift Pressure PRV
The power shift pressure PRV is used to destroke the main pump