CASE ASSEM. 4Y0380 - Caterpillar

Inputs
The machine has several different types of input devices. The ECM receives machine status information from the input devices and determines the correct output action that is needed in order to control machine operations based on memory and software parameters. The machine utilizes the following types of inputs: switch type and sensor type. Switches provide signals to the switch inputs of the ECM. The possible outputs of a switch are listed: an open signal, a grounded signal and + battery signal. Sensors provide an electrical signal to the ECM that constantly changes. The sensor input to the ECM can be one of several different types of electrical signals such as: pulse width modulated (PWM) signals, voltage signals and frequency input signals. Each possible input to the ECM is listed in the tables for the 70-pin connectors.Inputs provide information to the ECM in the form of sensors or switches.Sensors
Sensors provide information to the ECM about the intent of the operator or changing conditions. The sensor signal changes proportionally to the changing of operator input or changing conditions. The following types of sensor signals are used by the ECM.Frequency - The sensor produces a signal and the frequency (Hz) varies as the condition changes.Pulse width modulated - The sensor produces a signal. The duty cycle of the signal varies as the condition changes. The frequency of this signal is constant.Analog - The ECM measures the voltage that is associated to a specific condition of the control.Hydraulic Temperature Sensor
Illustration 3 g03372390The ECM receives signals from the hydraulic oil temperature sensor as an analog signal. The sensor is a passive sensor. The voltage output of the sensor changes proportionally to the temperature of the hydraulic oil. Switches
Switches provide an open signal, a ground signal, or a +battery signal to the inputs of the ECM. Switches are open or closed.
When a switch is open, no signal is provided to the corresponding input of the ECM. This “no signal” condition is also called “floating”.
When a switch is closed, a ground signal or a +battery signal is provided to the corresponding input of the ECM.Implement lockout Switch
Illustration 4 g03346014The implement lockout switch is a two pole switch. The switch has a normally connected and a normally open contact. When the switch is not depressed the normally connected contact is connected to the return, and the normally open contact floats to a high voltage state. When the switch is depressed, the normally open contact is connected to the return and the normally connected contact floats to a high voltage state. Based on the voltage state of the two ECM contacts, the ECM determines if the switch is depressed. 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.Coils
Blade Float Detent
Illustration 5 g03675233The blade float detent is an electrical coil that is energized by the ECM. When the coil is energized, the solenoid creates an electromagnetic field that holds