I've had my 2010 D4 for almost two years now and the entire time it's been plagued by "suspension fault" warnings that appear while going off-road:
C1130-66 (2C) Air spring air supply - Algorithm based failure - signal has too many transitions/events

Indy service hasn't been able to figure it out. I did end up having my rear crosslink valve replaced recently after the car dropped to bump stops and complained about one of the valves being stuck open, but since then the "too many transitions" fault seems to have been coming on even more quickly.

I had also noticed that the 4WD Info screen would tend to show the wheel heights as uneven, the compressor would come on frequently despite no evidence of a leak and the car would do some kind of self levelling fairly often after coming to a stop, even at normal height. And to top it all off, the damn thing looked lop-sided most of the time with the rear left corner noticeably closer to the ground than the right.

So FINALLY I got around to experimenting with the height sensor calibration routine in the IIDtool app. It's slightly clunky because the car doesn't respond immediately to your taps on the up and down buttons, but other than that it's very straightforward. Turns out my wheels heights were all over the place!

I went to work in my remote office yesterday... got a favourite spot in the back corner of the Mt Mee forest that gets 4G reception from across the valley... and the Disco has never felt so good, on the bitumen or in rock crawl mode. The 4WD Info screen shows level wheels on level ground now. The compressor really only came on when you'd expect it to. And not a single C1130-66 error.

Just wanted to add this to the searchable archives here in case anybody else starts getting suspension warnings that don't make sense.