If fluid level and the obvious things look ok then whilst waiting for Techstream you can manually check for, read and clear codes. It’s very straight forward. If you have DTCs you’ll get flashing OFF light two digit sequences with a pause in between codes. Note the sequences then clear them. DTCs in the system can be a bit unreliable, or not even trigger, but it’s still worth checking initially. Probably worth checking the integrity of your three height sensor mechanisms too.
How to pull codes. Ignition off, jump TC and E1 in the DLC1 connector, which is under the hood on passenger side fender, ignition on and you could get the OFF light flashing two digit sequences to decipher - but if you just want to clear any DTCs push the brake pedal 9 times in less than 3 seconds. Ignition off and remove the jumper and see what the result is. If you immediately go back to a fault state then you've got a real fault (as opposed to a spurious transient) that needs to be followed through.
You’ll obviously want to check and adjust your neutral pressures too. Not only do the neutral pressures determine how effective your damping is they also influence your load & pax carrying capacity. Too high pressure reduces your total load capacity (max system pressure is the combination of neutral pressure + load induced pressure) and potentially forces the system to default into L unnecessarily.
