Repair-It

It seems like the system typically uses the compressor to return air to the tank, and tank pressure to lift the springs. I wonder if the compressor is weak and I had less air mass in the system which made it easier to push back to the tank. Maybe the compressor is worn after all.

Tried a whole bunch of cycles of each spring. Seems like the fronts aren’t responding. I wonder if should just get one of these since I’m at 18Xk miles.

https://rebuildmastertech.com/rebuilt-a ... 2011-2021/

The cheaper dongle worked fine once I downloaded driver and figured out it was on com 6 (software auto looked at com3/4). System air mass appears fine (it’s just a calc based on pressures at all 4 corners and the tank). About 202.0 bar-liters, varies slightly depending on balance up to like 206.0 ...

Still has the unable-to-achieve ride height code, which I think may be due to nitrogen tank overpressurization because of the too-much-mass code I got while filling. Instead of guessing, I just ordered both dongles and will buy the AlfaOBD software when they come in. If the cheap one works, great ...

It set the code again so I need to troubleshoot and/or repair. Have any time available tonight or tomorrow since you said some of the diagnosis is probably Benz-tool-specific?

Looks like about $60 for the software, and I think they recommend the "multipin" version of this thing for about $240 for PC (I don't have any android stuff):
http://www.obdkey.com/obd_orders.asp?
OBDKey® Multipin Bluetooth

So $300 even.

I wonder if there's some other hardware I could use.

It now flashes a service air suspension warning briefly at initial gear shift that then goes away. I wonder what tool would allow me to access the air mass calculation diagnostic.

Probably cheaper, less corrosion resistant system components. But maybe not.

I don't think it's as "closed" as people think. I think it's all about starting dry and trying to stay that way as long as reasonable. No reason to start off with crappy shop air.

Set the underboost code again this week. I'd say it's been 5 months since the last one, but it was out of service about 3 weeks due to coolant leak chasing and my lack of availability, and a full month with the deer hit/bumper replacement. So I guess it's only been like 3 months.

With 3 month ...