HOSE 2172180 - Caterpillar

Illustration 5 g01213764
The torque converter temperature sensor that is located on the torque converter is a two wire passive thermistor type sensor. This type of sensor is used to measure the temperatures of the coolant, oil, and the inlet air. As the temperature of the torque converter oil changes, the resistance in the sensor will change. This change in resistance changes the voltage that is seen by the ECM for the sensor.Input Speed Sensor(Torque Converter Output Speed)
Illustration 6 g01213770
The speed sensor is an input to the ECU. The sensor informs the Transmission ECU about the speed of the transmission input shaft which is the Torque Converter Output speed. The ECU uses the information from the sensor in order to validate the Torque Converter Lockup Clutch operation. When the speed sensor fails to give a signal in proper proportion to the Engine speed and transmission output speed sensors an amber warning lamp is activated. The ECU also uses the information to aid in calibration of the transmission clutches. The sensor connects to the ECU through contacts J1-6 and contact J1-7. Position Sensor (Left Pedal)
Illustration 7 g00779650
Position Sensor (Left Brake Pedal)The position sensor (left brake pedal) sends an input to the ECM. The sensor will continuously update the transmission ECM on the position of the left pedal. The left pedal position sends a change in the input signal to the transmission ECM. The ECM records the change of position. Then, the ECM activates the appropriate solenoid valve.The position sensor (left brake pedal) is a PWM sensor. The sensor continuously generates a PWM signal. The duty cycle varies in proportion to the position of the lever. The ECM receives the PWM signal from the position sensor. The ECM measures the duty cycle in order to determine the position of the lever. The frequency of the sensor signal is constant at 500 Hz. The machine electrical system provides +battery voltage to the lever position sensor for operating power.Switches
Switches can provide three types of switch inputs to the transmission electronic control module (ECM):an open signal, a ground signal and a +battery signal. Switches are open or closed.
When the switch is open, no signal is provided to the corresponding input of the transmission ECM.
When a switch is closed, a ground signal or a +battery signal is provided to the corresponding input of the transmission ECM. Start Switch (Key)
Illustration 8 g02722514
Key Start SwitchThe key start switch is an input of the transmission electronic control module (ECM). The key start switch informs the transmission ECM of an attempt to start the engine. The transmission ECM then initiates the neutral start function. During normal machine operation, the start terminal of the key start switch is open. When the key start switch is turned to the START position, the start terminal closes to the +battery and the +battery voltage is present at connector contact J2-1 of the transmission ECM. When all starting conditions are satisfied, the transmission ECM sends a +battery signal to the connector contact J2-7 for the start relay and