WORM 0516203 - Caterpillar

Illustration 1 g02352857
Ride Control Valve located in the Implement Control Valve stack (1) Ride Control Valve (2) Rod End (RE) Check Solenoid Valve 1 (3) Balance Solenoid Valve 2 (4) Head End (HE) Check Solenoid Valve 3Three solenoid valves are used for electronic control of the attachment Ride Control System.The Transmission ECM controls the three solenoid valves with output driver circuits. The Transmission ECM will use Pulse Width Modulated (PWM) driver circuits operating in an ON/OFF mode to activate the three solenoids. The solenoids will either be in the OFF (de-energized) state or the ON (energized) state.The Transmission ECM will use the following control logic to control the system:
In the AUTO mode, the Transmission ECM will not enable ride control when machine travel speed is less than the configured activation speed. The default activation speed in both directions is 9.7 km/h (6 mph). The activation speed can be configured using Cat ET or the monitor display.
When the ride control function is OFF, the Balance Solenoid Valve 2 will be energized.
When the ride control mode is AUTO with machine speed less than activation speed, ride control will not be active. The Balance Solenoid Valve 2 will be energized.When the balance solenoid valve is energized, the balance valve spool will shift to block supply pressure from the ride control accumulator and drain any accumulator pressure to tank. As pressure in the head end of the lift cylinders increase, the spool will be forced to a position that will allow the supply pressure to charge the ride control accumulator.
When ride control is in AUTO and the ground speed is greater speed than the activation speed, the ECM will de-energize the Balance Solenoid Valve 2. Accumulator pressure will be open to the head end cylinder pressure.
After the balance solenoid is de-energized, the ECM will not energize the Head End (HE) Check Solenoid Valve 3 or the Rod End (RE) Check Solenoid Valve 1 for a default period of 3 seconds. This configurable delay time allows accumulator pressure on one end of the balance valve spool to equalize (balance) with the cylinder head end pressure on the other end of the spool. This balanced pressure will keep the spool in the hold position. Accumulator pressure will be blocked from the oil supply and from the tank.
After the balance delay, the Transmission ECM will energize both of the check valve solenoids.When energized, the Head End (HE) Check Solenoid Valve 3 will relieve the check valve holding pressure. Accumulator pressure will then flow past the check valve into or out of the head end of the lift cylinders.The energized Rod End (RE) Check Solenoid Valve 1 will relieve the check valve holding pressure allowing oil flow to tank or back into the rod end from the lines. Oil in the cylinder rod ends will then be pulled into or out of the cylinders as the rod moves up and down. This action and the accumulator pressure in the head end of the cylinders will dampen the