HOUSING AS 8N8464 - Caterpillar

Illustration 2 g03372378
Hydraulic Oil Temperature Sensor
The temperature sensor for the hydraulic oil informs the ECM of the temperature of the hydraulic system oil.The sensor is designed internally to change resistance based on the temperature of the hydraulic oil. The Implement ECM uses up a pull resistor to receive sensor voltage and convert the voltage to a temperature reading. The resistance range for this sensor is 33,650 ohms at −40° C (−40° F)to 18.6 ohms at 150° C (302° F).Pressure Sensors
Main Hydraulic Valve Supply Pressure Sensor
Illustration 3 g02571841The main hydraulic valve supply pressure sensor sends a PWM signal to the Implement ECM indicating system pressure. The duty cycle of the signal will vary in proportion to the system pressure. These PWM signals are inputs to the Implement ECM.Position Sensors
Lift/Tilt Lever Position Sensor
Illustration 4 g06058712The joystick lift position sensor sends a Pulse Width Modulated (PWM) signal to the Implement ECM indicating the position of the lift control lever. The position sensor is located in the base of the joystick.When the operator moves the joystick, the Implement ECM analyzes the signal from the joystick position sensor. The Implement ECM uses the sensor information, along with other conditions, to control the implement valve solenoids.Switches
Implement Lockout Switch
Illustration 5 g03015758The Implement ECM controls the operation of the Implement Pilot Supply Solenoid according to the position of the Hydraulic Lockout Switch. Certain fault conditions will also cause the Implement ECM to use the solenoid valve to disable hydraulic operation.When the switch is in the UNLOCK position, the normally closed switch contacts will ground the input circuit at ECM contact J1-34 and J1-33 is opened. When the ECM detects this grounded circuit, the ECM will energize the implement pilot supply solenoid. The energized solenoid allows pilot oil to be supplied to the implement control valve.When the switch is in the LOCK position, the normally open switch contacts will ground the input circuit at ECM contact J1-33 and J1-34 is opened. When the ECM detects this grounded circuit, the ECM de-energizes the ON/OFF output for the Implement Pilot Supply Solenoid. Pilot oil is blocked from the implement control valve.Filter Bypass Switch
Illustration 6 g03015918The bypass switch is a pressure switch that shows whether the filter is plugged and the filter is being bypassed. The oil filter bypass switch is a normally closed switch activating at 497 60 kPa (72 8.7 psi) and deactivating at 340 40 kPa (49 5.8 psi). The hydraulic filter bypass switch provides a ground to the ECM when activated.This switch is one of the inputs that is used to drive the "system indicator" in the instrument cluster. This indicator is turned ON when the switch is in the closed position and the oil temperature is greater than 52° C (126° F) with the engine running.Outputs
The ECMs respond 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. The outputs of the ECM are listed in tables .Solenoids
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