Suspension Fault - Normal Height Only - Pressure does not decrease

[NikolaiRostof]

Hello,

I have been getting the "Suspension Fault - Normal Height Only" Error for a couple months. It was intermittent at first, but increased in severity over time. I finally bought the RSW software, and found the error was "pressure does not decrease when venting gallery." Here are the stats:

2005 LR3 V8
AMK compressor - it was replaced before I purchased it.
Checked the dryer unit - desiccant was good, but I put it in the oven for a bit anyway - no change
Checked exhaust valve - seems to be lubed well
Tested the pilot valve solenoid - 16 ohms - ticks when power is connected
Tested Relay
Took apart compressor - cleaned everything
Removed exhaust line to confirm silencer is not the problem - I can blow through it easily with my mouth
Replaced pressure sensor
Checked the wire loom by the LHF tire (I have over-sized tires that rub) - I moved the loom out of the way of the tire, but saw no breaks, and the protective sheath is still intact.
Removed the main fuse overnight, and the suspension doesn't sink
I have noticed the rear finishes lowering about a half second slower than the front.

The weird bit is it will work fine for hours at a time, or sometimes not at all.

I have done some fiddling, and have found the indicated pressure will randomly decrease from 240 ish PSI to 30-60 psi before it kicks the fault. When I clear the fault, and select Off road height, the pressure will show correctly <200psi immediately. This leads me to believe this is an issue with the electronics or a connection somewhere (it is also why I changed the pressure sensor).

I can always clear the fault while selecting off-road mode then drop it back to normal height to fix the issue for 1+ hours.


I also get an error from the instrument panel indicating it lost connectivity with the ride height control module, but this doesn't happen every time, so I don't know if it is related.

Any ideas would be appreciated.

Thanks,
David

 

[Houm_WA]

I think you could benefit from getting the latest 'n greatest EAS software patch.

 

[jhilgart]

I've been having a very similar issue, but with the Hitachi compressor. I did the whole compressor fix with new desiccant, filters, piston seal etc. My compressor will run for about 5mins when I start my 06' LR3, but then I get the "Suspension Normal Height only" message.
I've read the temperature sensor can be faulty along with potential blockage in the valve block manifolds. Did you inspect those? I haven't gotten around to doing that, but since everything looks good on my compressor, I'm wondering If I need a dealer software reboot, or to clean-out the manifolds.

 

[NikolaiRostof]

I haven't had time to check the valve blocks, but I have begun to suspect them. I noticed the truck rocks a bit before the fault occurs (while parked, it is pretty slight). I have had the truck for 2 year before I started having this issue, so I don't know if a software patch will help, but I should probably get everything up to date anyway.


Jhilgart: your problem sounds different. My compressor doesn't run until the fault is cleared, then it works fine forward a while until it faults during a random height adjustment. Finding out the exact fault code will help you pinpoint the problem.

 

[jhilgart]

Thanks for the info David - I got fault code C1A20-64 Pressure increases too slowly when venting gallery, but that was pulled by my local shop before I rebuilt the air compressor(and the amber light is still on) I just have an OBDII(OBDLINK MX) which can clear most codes, but I don't have access to the ECU codes, so I may need to get the RSW software like you did.

Just a thought but have you checked the ride height sensors? Sounds like you may have a wiring issue. Or have you pulled the comp fuse for a couple days?(for self leveling).
Also there' a couple good YouTube videos about how to access the valve blocks and cleaning them as well.

 

[sonicpix]

I started having problems over six months ago. I got a suspension fault error, but it ran at normal height. Then it would sometimes lower and sometimes ride normal, very randomly.

I bought a kit to rebuild the Hitachi. Got it back from my mechanic, and second day i heard a clunk and thought "no way". After replacing the relay and checking the faults and ripping out most of my interior looking for frayed wires, this weekend I pulled out the compressor and found what I feared....a cracked piston rod.

Now it looks like I need to get a new compressor. I'm most likely getting a Hitachi because it avoids the reprogramming. But they are also about $150 CDN more because of this.

Any advice would be helpful.

2006 LR3 HSE

 

[morrisdl]

I used to readily find 'broken' Hitachi compressors readily at the local rover dealer, but I think LR-corp has a core return on these now. Most times they replace them its just the seal or clogged dryer. Still worth bringing them some starbucks and asking. I have rebuilt mine twice from 'broken' ones and get about 65k miles from the rebuilds. YMMV - I use mine is adverse conditions.

Getting the RS rock slider off is the only hard part of the job. BTW - I only use the two bottom mounting bolts to the frame. The top bolt was not worth it.

I had the pressure not decreasing message and it was the vent tube was disconnected.

I saw a local RRS guy moved his compressor to the 2nd battery box. Its on my todo list if I ever end up going to an AMK.

 

[jhilgart]

Morrisdl- which part of the vent tube was disconnected ?
After my rebuild, once I start it up, I've noticed a much louder venting when the fault kicks on(usually after a minute or so) . But it's hard to pinpoint because it doesn't vent very often.

I had the pressure not decreasing message and it was the vent tube was disconnected.

 

[morrisdl]

I think its the bigger of the two black hoses on the rear. I think the smaller goes to a filter behind the left tailight. Triple check everything for leaks with a spray bottle of dish soap water. good luck.

 

[jhilgart]

Out of curiosity did you ever find the issue related to your suspension fault?

after doing a compressor rebuild kit I've noticed the back will rise quickly but the front will rise very slowly, does anyone know what this might be related to? Valve blockage?