SHAFT 0049363 - Caterpillar

Steer Motor Speed Sensor
Illustration 5 g03509416
Location of Steer Motor speed sensor (4) "Steering Speed" sensor (two sensors)The Steering Motor Speed Sensor is mounted on the rear of the Hydraulic Steering Motor.The machine ECM controls the operation of the Differential Steering System. The machine ECM monitors and controls the steering system based on the input signals that are received from the following components:
The status of the parking brake switch.
The position input signals from the Directional "(FNR)" switch.
The two Steer Position sensors that are installed in the base of the Speed/Direction (Tiller) handle.
The speed of the Hydraulic Steering Motor as indicated by the two Steering Motor Speed Sensor inputs.The speed sensor for the steering motor signals the tractor ECM of the speed that the steering motor is rotating. The speed sensor for the steering motor also signals the power train ECM of the direction that the steering motor is rotating.The speed sensor sends two proportional signals to the ECM. The signals are frequency modulated signals. The signals are directly proportional to the rpm of the steering motor. The sensor can produce a frequency from 1 Hz to 3500 Hz. The signals are received on connector J2 on pins 34 and 35 of the machine ECM.The ECM monitors the speed sensor for abnormal frequencies or abnormal pulse width signals. If a fault occurs, a diagnostic code will be set and a warning will be generated. The steering system will then operate in an open loop mode.Hydraulic Tank Temperature Sensor
Illustration 6 g03509325
Location of hydraulic tank temperature sensor (6) "Hydraulic Tank Oil" temperature sensorThe hydraulic tank temperature sensor is installed in the side of the hydraulic oil tank. The temperature sensor is a resistive input sensor. The ECM detects changes in resistance in the sensor and uses that change to monitor the temperature of the hydraulic oil.Switches
Switch Inputs
Switches provide input signals to the ECM. When a switch is moved to a position that will cause the switch contacts to close, an open signal, a grounded signal, or a voltage signal will be detected on the input circuit of the machine ECM.Switch to Ground / Voltage Inputs
Switches will provide one of the following types of input signals to the ECM:
An open signal
A ground signal
A voltage signalThe contacts of a switch have two states of contact. The switch contacts are open or the switch contacts are closed.
When switch contacts are open, no signal is provided to the corresponding input of the ECM. This "no signal" condition is also referred to as floating.
When switch contacts are closed, either a ground signal or voltage signal is passed through the switch contacts to the corresponding input of the ECM. Switch to ground type input circuits have an internal ECM "pull up voltage" that is present at the ECM contacts. A voltage that is above normal is internally connected to the input of the machine ECM through a resistor. This resistor allows the ECM to detect a problem in the switch circuit. During normal operation, the signal of the switch will