Remove both wires from the CSS, determine which one is the power supply and re-connect it. The remaining wire is the one that goes to earth via the hydraulic switches on the transmission. You should find that the CSS is no longer extended (or at least is free to compress). Assuming that to be the case then you have proved that you have a switched earth problem which will either be the wiring (commonly they are incorrectly installed at the terminal block on the lower left side of the bell housing) or one or both of your pressure switches are stuck in the closed position.
Re-connect the earth wire at the CSS and disconnect the wire from the right hydraulic switch. If the solenoid is now de-energised then you know that it is this switch that is permanently closed (once you've check for correct connections as described). If it's still energised then disconnect the wire at the left switch and observe same. If the CSS is energised with both wires disconnected then you have a false earth connection somewhere.
