My 2003 XJ6 is way too hight at the rear with a C2302 Leveling plausibility error. I tried to run the deflate function in SDD v131 and it only deflated 3 corners. The rear left stayed high. Incidentally I earlier had an error saying I had a short circuit to battery in the left rear shock, but that error disappeared when i replaced relay R1

Any ideas? Could it the the valve block, the ASM, something electrical? Is it possible it can be a faulty height sensor? Visually the look ok.

 

My guess would be your valve block. Looks like the solenoid for that strut is stuck. Fortunately there's a new one on ebay for $100 bucks.
I just bought one myself since it's cheap and I'm rebuilding my air system, but have yet to install it.

You can try loosening all the lines at the air valve block to lower all struts manually then try running the leveling program in SDD before buying new parts though.

 

If I deflate (remove air connections) all shocks, they will all inflate again when I start the car, but the deflate program in SDD will only deflate 3 corners. Seems there some sort of message that won't reach the rear left shock.

 

Looks like a stuck solenoid in the valve block. Or maybe the height sensor to that strut is bad causing the car to think that it's already deflated.
Try running the calibration program in SDD to see what the height reading is for that strut.

 

Thanks for replying. I ran the calibration program while the car was raised. Seems it was a big mistake. It just ran the compressor constantly until I tried to abort and the program and it crashed. Now I'm a a bit hesitant to run it again.

I've never run the height calibration before so I'm not quite sure what's supposed to happen, but when I started it it said leveling (i believe) in progress and it just ran the compressor without anything really happening. I thought I would be able to set the height myself. Maybe that's supposed to happen after it tries to level?

Is there a way I can measure/check the valve block, to see that it's really the culprit?

 

Sorry to hear,
You can try switching the height sensor to the other side. If the pattern repeats a the opposite end then we found the culprit. If not, then looks like a stuck solenoid on the valve block.

 

Good idea, I'll try that.