STUD 1003753 - Caterpillar

Electronic Control System
Illustration 1 g03702004
Diagram of the machine control electronic communication system
(1) Machine ECM
(2) Implement ECM
(3) Travel pedal
(4) Engine ECM
(5) CAN A data link
(6) Machine monitor
(7) Machine security system
(8) CAN B data link
(9) Operator control panel
(10) Product link
(11) Service connector
(12) Communication Adapter III
(13) Electronic Technician (ET) The following will cover information that pertains primarily with the return system and components that are controlled by the machine ECM.When using this manual for the troubleshooting of the electrical system circuits, the complete electrical system schematic for your machine should also be used. Quick reference electrical connection diagrams are included throughout this manual. However, these diagrams do not show the machine wiring harness connections that are part of the circuit. The complete electrical system schematic illustrate all machine wiring harness connectors and the locations on the machine.
Illustration 2 g03701860
Electronic control modules are located to left rear side of the machine
(1) Machine ECM
(2) Implement ECM Electronic Control Module (ECM)
Machine ECM
The machine ECM is the control module that will use the programmed control logic to manage the operation of most of the machine functions. The machine ECM will use the data from the various input devices to determine the appropriate output response to operator commands.The machine ECM determines all of the appropriate output commands and communicates this information to the Implement ECM on the SAE J1939 (CAN) data link.The machine ECM will activate outputs in order to energize or de-energize solenoids that will control the installed machine functions.
Illustration 3 g03701879
Machine ECM connectors
(1) J1 connector
(2) J2 connector Pin Locations for Machine ECM
Illustration 4 g03701995
Machine ECM connector (70-pin)
Table 1
Machine ECM - J1 Contact Connections
Pin Location Function Description
40 Hydraulic oil clog switch Switch to ground input
Table 2
Machine ECM - J2 Contact Connections
Pin Location Function Description
63 Switch return Return (ECM ground) 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 return system contains the hydraulic oil filter clog pressure switch.Pressure Switches
Illustration 5 g02332474
Pressure switch
Note: The values in Table 3 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 3
Actuation Pressure 490 49 kPa
Deactuation Pressure 294 kPa minimum
Rating + 12V to + 32 V DC
0.01 Amp to 1 Amp
Pressure Range 0 to 10 MPa