Front air suspension

[tanadaear]

LR4 2012 front suspension going down overnight and I’m getting some logical errors

RLM-Suspension

• C1A13-64 (AF) Pressure does not decrease when venting gallery - Algorithm based failure - signal plausibility failure
  ( on 01-02-2025 09:28:14 at 183183 km )
• C1130-66 (28) Air spring air supply - Algorithm based failure - signal has too many transitions/events
  ( on 01-02-2025 11:00:33 at 183209 km )

Gap tool is showing an interesting sawtooth pattern. It shows the air pressure in the gallery, slowly creeping up and then the exhaust valve opening it again to dump it.

Since the front end is collapsing overnight, and I’m seeing this pressure creep issue, I’m leaning towards some kind of valve failure in the front control block

The air reservoir valve might be leaking as well, but that wouldn’t count for the front suspension collapse unless they both happen to be leaking

It’s the middle of winter here so I don’t have a warm place where I can spray water and soap all over my front system to check for possible air leaks. Does anybody have any other suggestions? I’m leaning to ordering a front air block and swapping that in to see if it fixes the problem.

 

[ftillier]

If you're on your original compressor, the desiccant likely turned to dust and some of it is preventing the solenoid from closing all the way. You'll want to replace the desiccant (or whole compressor unit), and clean the valves blocks out.

 

[tanadaear]

If you're on your original compressor, the desiccant likely turned to dust and some of it is preventing the solenoid from closing all the way. You'll want to replace the desiccant (or whole compressor unit), and clean the valves blocks out.

Thanks for the suggestion

 

[Longtrail]

Perhaps look at my journey with suspension issues in this thread (I have a similar code and falling overnight):

2012 LR4 Reluctant to lower from off-road suspension mode

Hi Folks, I just rebuilt the front suspension valve block (new o-rings) and now the LR4 seems to stay up over night (good news), the problem I have existed before doing this work and appears to be in the rear. Here's a summary of the issue. 1) I select off-road as the suspension mode and the...

www.landroverworld.org

I would absolutely start with new o'rings per the thread and clean/service the three valve blocks (front, middle, rear). O'rings have caused folks to have issues (wrong size), I strongly recommend reading the whole thread and paying attention to where I sourced o'rings; others have followed and had decent luck. Also, I post some YouTube video links that I hope will help you when doing the valves.

In the end my computer module had the wrong firmware, it was flashed for a Hitachi but an AMK compressor had been installed.