CONTROL GP-JOYSTICK 2305591 - Caterpillar

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 inputs to ECMs are listed in table.Temperature Sensors
Axle Oil Temperature Sensor
Illustration 2 g03389644The temperature sensor for the hydraulic oil informs the ECM of the temperature of the hydraulic system oil.The sensor sends a PMW signal to the Transmission ECM indicating axle oil temperature. The duty cycle range for this sensor is 10.01% at −40° C (−40° F) to 89.26% at 120° C (248° F).The Brake System uses one temperature sensor for the front axle oil and one temperature sensor for the rear axle oil.Pressure Sensors
Illustration 3 g03389651Brake Pressure Sensor
The brake pressure sensor informs the power train ECM of brake system pressure. The pressure sensor output is a pulse width modulated signal. The duty cycle of the signals will vary in proportion to the system pressure. These PWM signals are inputs to the Power train ECM. The Power train ECM provides 8 V supply and 8 V return for the sensor.Position Sensors
Illustration 4 g03389655Left Pedal Position Sensor
The pedal position sensor determines the position of the torque converter pedal. The sensor sends a PWM signal to the power train ECM. The power train ECM monitors the signal. Then, the power train ECM calculates the position of the pedal from the signal.Switches
Switches provide one of the following types of input to the ECMs.
Open
Ground (-)
Battery (+)Switches are devises that have two states, Open and Closed.
When a switch is open, no signal is provided to the corresponding input of the ECM. This condition is also referred to as floating.
When a switch is closed, a ground signal (-) or a battery signal (+) is provided to the corresponding input of the ECM.Service Brake Position Switch
Illustration 5 g03389656The brake pedal position switch is a mechanical switch that is used to determine if the operator is depressing the service brakes pedal. This switch has two outputs, one that is normally closed and one that is normally open. This switch provides a ground signal to the engine ECM. When the operator activates the switch, the outputs become reversed.Ignition Switch
Illustration 6 g03389670The ignition switch is a four position, two contact switch. The transmission ECM receives battery (+) voltage from the ignition switch in the (RUN), (START), and (AID) positions.Data Link
Cat Data Link
The Cat Data Link is an input/output of the ECM. The data link uses the connector for the service port in order to communicate with the Caterpillar Electronic Technician. A data link connection is provided for the product link.Note: The control for the product link provides a global positioning system for the machine.The data link is bidirectional. The bidirectional link allows the ECM to input information and output information. The data link consists of the following parts: internal ECM circuits, the related