FLUID-UREA 3508734 - Caterpillar

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.Solenoids
On/Off Solenoids
Illustration 18 g01158530Note: The values in Table 11 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 11
Rated Voltage 24 VDC
Coil Resistance 32.0 3.2Ω (T=20° C) The On/Off solenoids include:
Swing brake solenoid
Travel speed solenoid
Straight travel solenoid
Hydraulic lock solenoid
Swing priority solenoidProportional Reducing Solenoid Valve
Illustration 19 g02703776Note: The values in Table 12 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 12
Current Range 0 mA ~ 700 mA
Coil Resistance 11.5 0.5Ω (T=20° C)
Illustration 20 g02263554
A - Port pressure (kPa) vs Current (mA)
The proportional reducing solenoid valve is used on machines equipped with tool control. The P-Port is blocked and does not allow pressure to the A-port. Therefore, the machine ECM must apply current to the PRV in order to sent pressure to the A-port of the PRV.The PRV's include:
Negative Flow Control 1 Limit PRV
Negative Flow Control 2 Limit PRV
Power Shift Pressure PRVReverse Proportional Reducing Solenoid Valve
Illustration 21 g02304374
Valve cutaway, hydraulic schematic symbol, and electrical connector designation
Note: The values in Table 13 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 13
Current Range 0 mA ~ 700 mA
Coil Resistance 11.5 0.5Ω (T=20° C)
Illustration 22 g02304414Reverse PRV's have the P-port open to the A-port with no current applied. Therefore, the machine ECM applies current to the PRV in order to decrease the pressure at the A-port.The reverse PRV's include:
Boom Regeneration PRVData Link
Cat Data Link
Illustration 23 g02694217
Schematic of the “Cat Data Link” Circuit
The Cat Data Link is an input and an output of the Machine ECM. The Cat Data Link connects to the Machine ECM at connector contact J2-16 and J2-25. The data link is designed to carry communications between the controller and the monitor. The data link is not a visible component. The data link consists of internal control circuits and a harness wiring. The data link is bidirectional. The controller can receive information and the controller can send information through the data link. The controller sends information about the fuel level, temperature of the engine coolant, and many other signals to the monitor panel.CAN Data Link
Illustration 24 g02694576
Schematic of the "CAN Data Link" Circuit
The CAN data link is used for communication between the following modules: Machine ECM, Switch Panel and Monitor. Two 120 Ohm terminating resistors must be installed in the wiring harness in order for the CAN data link to function properly.Action Alarm
The action alarm SOUNDS in order to alert the operator when a high emergency condition is present. For example, the engine oil pressure decreases below a set value.Travel Alarm
The travel alarm SOUNDS in order to alert the area that the machine is moving.