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| Illustration 1 | g00796645 |
(1) Tilt control lever. (2) Lift control lever. (3) Auxiliary control lever. | |
Tilt control lever (1), lift control lever (2), and auxiliary control lever (3) are controlled manually by the operator. The control levers send electronic signals to the implement electronic control module (ECM). Then, the implement ECM sends the appropriate amount of current to the solenoid valve (pilot proportioning) on the pilot valve (oil manifold). The solenoid valve sends a low pressure signal to the main control valve. This signal causes a stem in the main control valve to move. Then, pump supply oil is sent to the implement cylinders. The cylinder rods will extend or the cylinder rods will retract.
The optional auxiliary implement system has an auxiliary pilot valve, an auxiliary control valve, and auxiliary cylinders. To control the auxiliary implement system, auxiliary control lever (3) is added in the operator station.
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| Illustration 2 | g00990029 |
Location of the Detent Coil | |
The electrohydraulic control is equipped with detent coils. The detent coils are electromagnets that hold the control levers (1, 2) in the full forward position, or full back positions. The levers are held in position until the detent coils are de-energized or the control levers are manually moved. The detent coils receive outputs from the implement ECM. The implement ECM activates the detent coils in order to hold the levers until the proper position of the work tool is reached. The detent coils have a connector with two contacts. One contact receives power from the corresponding connector contact of the implement ECM (J2-37, J1-12 and J1-18). The other contact of the coils join together returning to connector contact J1-7 and J2-3 of the ECM.
The lift lever has two detent coils. One detent coil holds the lever in the RAISE position. The other lever holds the lever in the LOWER position. The tilt lever has one detent coil that holds the lever in the TILTBACK position. The machine has an optional tilt lever detent coil for dump. The auxiliary lever does not have a detent coil.
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| Illustration 3 | g01038776 |
Joystick Control (4) Fine modulation switch (if equipped). (5) Switch (hydraulic lockout). | |
If the machine is equipped with a joystick control, the joystick control combines two-function levers or three-function levers into one control. The joystick is equipped with a pulse width modulated sensor for the lift, tilt, and the third function. The arrows that are going from right to left describe the lift function. The arrows that are going up and down are for the tilt function. The thumb lever controls the third function. The joystick control has soft detents. The detents in the joystick control are soft detents. The soft detents are controlled by the software within the implement ECM. As the joystick control is moved into the detent position, the linkage will travel to the kickout position that is preprogrammed. The joystick control should be released in order to automatically return to the HOLD position. The linkage movement will continue until the kickout is reached. Any 6° movement of the joystick control from the HOLD position will disable the detent. The soft detents will not be activated if the joystick control is held in the detent position for more than 1 second.
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| Illustration 4 | g01042748 |
Electrohydraulic Control (4) Fine modulation switch (if equipped). (5) Switch (hydraulic lockout). | |
Fine modulation switch (4) allows the operator to control the amount of current that is sent to the solenoid of the proportional valves. The fine modulation switch instructs the implement ECM to control the current. Use Caterpillar Electronic Technician (ET) in order to calibrate the fine modulation current. There are individual adjustments for fine modulation in both the lift function and the tilt function. Activating the fine modulation switch will allow more accurate control of the implements.
The switch (hydraulic lockout) (5 ) is used to disable the implement pilot system. When the switch is in the LOCKED position, the solenoid valve (hydraulic lockout) is de-energized. No pilot oil is allowed to flow through the pilot valve (oil manifold). When the switch is in the UNLOCKED position, the solenoid valve (hydraulic lockout) is energized. Pilot oil is allowed to flow through the pilot valve (oil manifold).