KIT-SPRING 8Y6860 - Caterpillar

Switches
Switches provide the following types of information to the ECM: open signals, ground signals, and +battery signals. 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.Start Switch (Key)
Illustration 1 g00497430
Start Switch (Key)
The key start switch is an input of the ECM. The switch connects to connector contact J2-1. The switch tells the ECM that the operator wants to start the engine. The ECM then initiates the neutral start function. Refer to the Systems Operation, "Neutral Start Function" section of this manual for more information. The signal is open during normal operation. The switch closes to the +battery when the switch is in the START position.The switch has a connector with four contacts. Contact 3 connects to the ECM. Contact 4 connects to battery voltage. Contact 2 connects to the engine shutdown control. Contact 1 connects to the main relay.Note: After the switch is initially turned to the START position, the switch will not return to the START position from the ON position. The switch must be turned to the OFF position. The switch can then be turned to the START position.The ECM does not record diagnostic codes that are related with the key start switch.Neutral Switch
The switch allows the operator to quickly shift the transmission to NEUTRAL from any gear. The switch has a connector with two contacts. The switch connects to the Transmission ECM through contact J1-43 and contact J2-63. See the Systems Operation, "Quick to Neutral Function" section of this manual for more information.Lockup Clutch Switch
The switch allows the operator to disable the lockup clutch in all gears. The switch has a connector with two contacts. The switch connects to the Transmission ECM through contact J2-23 and contact J2-61. The ground connection is switched between the two pins when the switch is toggled. The transmission will be limited to NEUTRAL and PARK when an invalid switch position is detected. Refer to the Systems Operation, "Lockup Clutch Disable Function" section of this manual for more information.Bypass Switch (Transmission Oil Filter)
Illustration 2 g01308999The switch allows oil to bypass the filter when the filter is plugged. The switch opens and the oil bypasses the filter. The switch connects to the Transmission ECM through contact J1-63 and contact J2-63.Sensors
Sensors provide information to inputs of the ECM about changing conditions. The ECM receives the following types of information:
Speed
Temperature
PositionThe sensor signal changes in a proportional manner in order to reflect the changing condition. The ECM sends the information to the gauges. The operator can view the information on the gauges. The ECM recognizes two types of sensor signals.Frequency - The sensor produces an AC signal. The AC signal frequency (Hz) varies as the condition changes.Pulse width modulated - The sensor produces a digital signal. The duty cycle of the digital signal varies as the condition