4 ... then to the 115 bar relief valve.

Should read "then to the pressure release solenoid valve."

I ran some more diagnostic tests. At the pump assembly, BRN-BLU (Brown wire with Blue stripe) is the pump control signal. It is active low, i.e., it goes to ground to activate the pump by energizing the relay. BRN-GRN activates the pressure release solenoid valve, again an active low signal, i.e., it goes to ground to energize the solenoid coil. The Solenoid Valve circuit is not active until about 5 seconds after the ignition is switched to run position.

By grounding the BRN-BLU line to the chassis, my pump will run (making a bit of a racket) and pump up the rear end about 4 inches until the 115 bar pressure switch opens and breaks the path to ground (I suppose it would go higher if I grounded the other side of the 115 bar switch). If I reconnect the "switch" connector to the box under the car and turn the ignition to run, after ~ 5 second lockout (possibly involving the GRN-RED wire) the system senses that the rear height is too high and the release solenoid actuates and bleeds off pressure until normal ride height is acheived. I still have not been able to force the rear end low enough for the "switch" to activate the pump, even with all pressure bled off manually. I don't think I have a problem with the color code transposition, however, based on these test results.

I still don't know if that missing 0.5 liters of fluid indicated a busted accumulator. Based on the volume of fluid pumping through the system, I'm guessing I have one good accumulator at least. I'm curious if there are special procedures for bleeding the system when installing new hydraulic components.

I'm guessing the 30 bar switch at the hydraulic T-connector is normally open (at zero pressure) and closes above 30 bar pressure. This sets the minimum pressure for the solenoid pressure bleed circuit. Joe