Repair-It

Got my first Service Suspension Immediately message on the Jeep this morning on the way to work (106 mi each way) about 80 miles into the drive.

Stopped a few miles shy of work to look at a couple basics and see if ride height was lower than normal. It stayed on the indicated "Aero" setting, which is about 50+mph normal ride height. Everything looked OK. Seemed like it was likely that the compressor hadn't responded for make up air and the computer had stopped trying to command it. I swapped the high-speed fan relay with the compressor relay just "because". 40 amp compressor fuse looked intact. Still had the error/code. Vehicle would not respond to any "raise" requests and just kept showing Aero-height (which is not normal under 50 unless in Sport mode).

Got to work and I pulled three suspension fuses to try to "reset" and have the system try again. After pulling those and cycling ignition and restarting the engine, I was able to command Off-road 1 and it raised. I couldn't hear if the compressor was running or not. I left it at Off-road 1 height parked and went into work. We'll see what it says when I get back out.

Also used on Tesla? https://rebuildmastertech.com/68204730a ... irR5JtIuwf

Interesting if I do need one:
Dorman 949-300
https://www.rockauto.com/en/moreinfo.ph ... 19&jsn=647

https://www.napaonline.com/en/p/NOE949300

It was about 16-18 degF when I got the message. I have read that these are apparently nitrogen filled "closed" systems (and therefore low moisture) when new, although apparently the system can draw in make-up air through a desiccant. With my age and mileage it wouldn't surprise me if there was some moisture and possible freezing. I wonder what I should start with if it reoccurs...

If there's a leaking rear bag that's making too-much-make up air required, at least they look relatively easy to change...
https://www.rockauto.com/info/899/A-301 ... Manual.pdf

No codes / issues on the drive home last night. Cycled all modes a bunch of times last night and couple times this morning and all seems ok, compressor sounds fine and run time is normal/brief only while changing.

I guess all is ok with just a reset.

Set an error message again about 45 miles into a trip up to Ski Sundown. Was about 10 degF at the time. I wonder if there's moisture in the system and cold temps wreak havoc. Perhaps I should purge and nitrogen refill...

I do have a grinding noise when I go over big bumps that I think is coming from the drivers strut area. Never seems to leak down, so I doubt it's related...

Front seems to lose ride height consistently in 24+ hours of sitting. I probably need to figure out how to isolate portions of the front end circuits to figure out where it's leaking (likely the strut assemblies?)

On my S550 I ran the suspension function diagnostic which pumps air all over the place and looks for change in ride height rate over time and while it was failing that test on the right front I actually heard the air leaking from the strut when it tried to inflate above a certain height.

So that's how I was able to be confident that it was a strut issue.

If you are still happy with the shock performance of those struts then maybe you would consider sending them to RMT like I did which has worked out great.

What's our best option between the two scan tools to get Jeep test functionality?

And just "cause" I left it in Offroad 1 (lifted) position all day at work on Thursday and it seemed to stay up 6-8 hours or so. I wonder if there's a scratch on the piston rod or bore assembly if they have a sliding seal. I guess this is thinking through the grinding noise and if there's sand/debris near/on some sliding surfaces. If they're an air bladder/rubber diaphragm then I have no good theories as to why offroad 1 would "help" hold air.