Have had the occasional EAS fault over the past 3 years, but clearing the stored failure codes has always fixed it in the past. However this time it wasn't enough, something had gotten bad enough for the error codes to re-appear instantly.

Did this in April 2017 to my 2003 L322 and all is still perfect. 13 months and still perfect as at 21 June-2018.

So - first the problem:
No lights on height controls and "Air Suspension Inactive" shows on message centre.
When I Read Codes --> front right and rear left valves failed.
Attempted to clear the faults, but they would not go away.

Further diagnosis:
Manually operate the valves (I built a small circuit board with some switches to plug in in place of the EAS computer at the front left 'A' pillar). ALL valves work fine. BUT the switches got hot, meaning there is a (too) large current being drawn to operate the valves. This would explain why the computer thinks the valves are faulty.
But the valves do work, hmmm, could it just be that the 14 year old air valve lubricant has degraded to become a sticky sludge or even simply evaporated away?

Valve Lubricant Refurb:
* With the car parked flat I put supports under all 4 lower suspension arms, then with my manual switches let all the air out of the 4 bags.
* The battery was then disconnected.
* Beneath the car (under the right hand front seat) is a cover panel for the valve body. I undid the air lines and the 4 mounting nuts in order to remove the valve body. The wiring clips were a little stiff, but eventually released properly.
* On my workbench I removed the valve casings (torx screws). There is a single valve for the storage tank and a multi-valve for the 4 corners.
* The tank valve 'slug' fell out, as did the rear right, but the other 3 were stuck. The valves themselves (under the slugs) were easy to remove but felt 'sticky'. The gaskets all looked fine, no cracks or flattening.
* A little WD40 and some patience got the other 3 slugs and valves out. The whole lot then got a good overnight soak in WD40 to soften any old, hardened lubricant.
* I cleaned off the WD40 with 60% alcohol (Glen20). 3 rinses and wipes with lint free cloth, then a rinse and an hour air dry. (I used some nylon fly screen over a lint free cloth a a drain board).
* All the internal parts were then sprayed with silicon lubricant and all excess allowed to drain off for over an hour. Latex gloves are recommended for the lubricating and re-assembly.
* The valves and slugs were put together, then the gaskets and clean casings refitted and the screws tightened down.
* Next the valve body was connected to the air lines and wiring and the 4 mounting nuts screwed up. Cover fitted.
* The battery was connected.
* I used my manual switches to lift all 4 corners off their supports.
* I used the instrument cluster buttons to run 'test 19 - Unlock' and 'test 21 Reset All Defect Codes'. Having the battery disconnected for a day should have done this too, but ...
* Finally I plugged in the EAS computer and nothing happened. But when I put the key in and turned it to Acc the height control normal LED came on and the car levelled itself.
* Remove the supports and happily drive off.

As I said at the beginning, it's all going very well ...
If the modern silicon lubricant works as well as I expect it to this should be a 'lifetime' fix. But I intend to repeat it about every 24 months anyway.

bye.

Last edited by bgennette on 21st Jun 2018 6:30am. Edited 8 times in total

Thanks for sharing, any Photo`s? 2007 TDV8 VSE
2003 TD6 gone.
2002 P38a gone
1999 P38a gone
1997 p38a gone
1993 VSE gone
1992 VSE gone
1966 Series 2a with V8 conversion gone

When you say silicon lubricant do you mean the one that's as clear as water or the silicon grease one?

This is a thin, clear liquid that comes in a spray can.
Within minutes of applying the carrier liquid completely evaporates leaving a non sticky, low friction layer that doesn't attract dust (maybe the silicon conducts any static charges away?)

I use it on all the drawer slides and hinges in my caravan and on the drive and glide bars on my cnc machine.

bye.