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| Illustration 1 | g01184486 |
Front of Center Console (1) Machine ECM circuit breaker (2) Display circuit breaker (3) Engine ECM circuit breaker | |
The following components are located on the circuit breaker panel:
- Machine ECM circuit breaker (1)
- Display circuit breaker (2)
- Engine ECM circuit breaker (3)
The circuit breaker panel is located on the front of the center console. A decal on the panel, below each circuit breaker, identifies the function of the circuit breaker.
These circuit breakers receive power when the main power relay is energized. The machine ECM receives power from the machine ECM circuit breaker (1). The EMS III display receives power from the display circuit breaker (2). The engine ECM receives power from the engine ECM circuit breaker (3).
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| Illustration 2 | g01184577 |
Inside the Center Console (4) "J1 " connector (5) Machine ECM (6) "J2 " connector (7) "CAN " resistor | |
Machine ECM (5) is mounted to the left side of the center console. The machine ECM controls the cooling fan system. This ECM has two 70-pin connectors. "J1" connector (4) is the top connector. "J2" connector (6) is the bottom connector.
Machine ECM (5) receives power from the machine ECM circuit breaker (1) at the following terminals:
- "J2-1"
- "J2-23"
- "J2-47"
The machine ECM is grounded at the following terminals:
- "J2-2"
- "J2-22"
- "J2-46"
The EMS III display provides machine ECM (5) with information about the hydraulic oil temperature through Cat Data Link lines. The Cat Data Link Lines are connected to terminal "J1-7" and terminal "J1-8". The engine ECM provides information about the engine coolant temperature, and information about the intake air temperature to the machine ECM. This information is delivered through CAN lines, which are connected to terminal "J1-6" and terminal "J1-18 "of the machine ECM.
System software compares the input which is gathered by the machine ECM through the data transfer to information which is stored in the ECM memory. The software evaluates the current conditions. The software then generates an output signal from terminal "J2-46" in order to control the cooling fan system within set parameters. The strength of this output signal is inversely proportional to the fan speed, the lower the output signal, and the faster the fan speed.
CAN resistor (7) is located near the machine ECM (5). This resistor is in the data communication circuit between the machine ECM and the engine ECM.
Note: Machine ECM (5) is programmed with self diagnostic logic. Service information can be accessed using the Caterpillar Monitoring System.
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| Illustration 3 | g01184607 |
Center Console (8) Hydraulic oil temperature gauge (9) EMS III display | |
EMS III display (9) is located on the center console. The display contains a 40-pin connector. The EMS III display receives power at terminal "1" of the 40 pin connector. The display is grounded at terminal 2 of the connector.
The EMS III display (9) monitors the resistance across the hydraulic oil temperature sender at terminal 8. The display shows the temperature reading which is on the hydraulic oil temperature gauge (8). The hydraulic oil temperature input is also transferred to the machine ECM (5) through the Cat Data Link lines. The Cat Data Link lines are connected to terminal "5", and connected to terminal "14" of the 40 pin connector.
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| Illustration 4 | g01184626 |
Front of Engine (10) "J2" connector (11) "J1" connector (12) Engine ECM | |
The right door in the hopper provides access to the engine ECM (12). The engine ECM has two 70-pin connectors. The "J1 "connector (11) transfers information between the machine harness and the engine ECM. The "J2" connector (10) monitors components which are located on the engine.
Engine ECM (12) receives power at the following terminals:
- "J1- 48"
- "J1-52"
- "J1-53"
The engine ECM is grounded at the following terminals:
- "J1-61"
- "J1-63"
- "J1-65"
CAN lines are connected to terminal "J1-34" and terminal "J1-50" of the engine ECM (12). The CAN lines allow the engine ECM to communicate with the machine ECM (5). "J2" connector (10) collects input from the engine coolant temperature sensor and from the intake air temperature sensor.
Note: The computer plug-in resistor (not shown) is located near the engine ECM (12). This resistor is located in the data communication circuit between the machine ECM and the engine ECM.
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| Illustration 5 | g01184670 |
Right Side of Hydraulic Oil Tank (13) Hydraulic oil temperature sender | |
The hydraulic oil temperature sender (13) is installed in the right side of the hydraulic tank. The hydraulic tank is located under the operator platform.
The hydraulic oil temperature sender (13) is a resistance type device. The EMS III display (9) measures the resistance through the sender. The display converts the resistance value into an analog output signal which drives the hydraulic oil temperature gauge. The EMS III display also transfers information about the hydraulic oil temperature to the machine ECM (5) .
In order to control the speed of the cooling fan, the machine ECM uses this input about the following:
- Engine coolant temperature
- Intake air temperature
- Hydraulic oil temperature
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| Illustration 6 | g01184708 |
Rear Right Side of Engine (14) Coolant temperature sensor | |
The coolant temperature sensor (14) is located on the right side of the engine. The engine compartment cover provides access to this component.
The coolant temperature sensor (14) provides an input signal to the engine ECM (12). The engine ECM transfers coolant temperature information to the machine ECM (5) through CAN lines.
In order to control the speed of the cooling fan, the machine ECM uses this input about the following:
- Engine coolant temperature
- Intake air temperature
- Hydraulic oil temperature
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| Illustration 7 | g01184780 |
Front of Engine (15) Intake air temperature sensor | |
The intake air temperature sensor (15) is located on the front of the engine. The engine compartment cover provides access to this component.
The intake air temperature sensor (15) provides an input signal to the engine ECM (12). The engine ECM transfers intake air temperature information to the machine ECM (5) through CAN lines.
In order to control the speed of the cooling fan, the machine ECM uses this input about the following:
- Engine coolant temperature
- Intake air temperature
- Hydraulic Oil temperature
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| Illustration 8 | g01184805 |
(16) Computer plug in resistor | |
The computer plug in resistor (16) is located near the engine ECM (5). This resistor is in the data communication circuit between the engine ECM and the machine ECM.