Hi @smurf thanks for the reassurance. over the past few days I've come to the same conclusion regarding Nitrogen and not oil to pressure the accumulator
The electronic controller is reporting an error code E1 which according to the user guide means low tank pressure. It's a shame it does state what the pressure should be set to.
I don't think I can test the pump until it's been repressurised , I did press the l pin on the Schrader connection and only a small amount of Nitrogen or air was expelled. suggesting a very low pressure.
All lines and connections look good so I am hoping it's just a matter of getting it up to the correct pressure to clear the Error code on the height controller for it to start working.
I need to find a local firm.willing to give it a pressure test/fill test without breaking the bank.
This is the system https://www.tein.co.jp/e/products/hybrid_wagon.html#:~:text=HYBRID WAGON Damper is fully,available (except some models).