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Air Suspension Light - and code C1A20

68K views 20 replies 7 participants last post by  christofbove  
#1 ·
I have a 2006 RRS HSE. For the past two months it has been code, and I have noticed the rear left side will sink down to bump stop over 2-3 days when parked. This week, I was seeing suspension warning light come on, about 30 seconds after start up. Compressor will start - inflate the ride height to normal, but then stop with the chime and warning light and message in the dash saying "Suspension Fault, Normal Ride Height Only" . The first couple of times it did this, the error would go away after a restart. But now it is consistently staying on. Car still drives normally. I think my compressor is original (I need to pull the cover to see if it is Hitachi or AMK)- and I'm at 113K miles. California is not humid - so my desiccant maybe has longer life than in places like Florida.

I had a friend with a code reader pull the code - "C1A20 pressure increases too slow when filling reservoir". We looked at compressor temp - read 55C (30 seconds after start up) - not sure if that is normal or high (outside temp was 60F or so).

After reading the forums, it looks like desiccant in compressor drier degrades, clogs value block (hence the minor leak (I assume back into the reservoir because rear left valve sticks open just a little ?) - and the desiccant is also clogging the compressor inlet (?) which leads to the warning.

I saw a few posts where people had change the compressor (or rebuilt it) , but it didn't fix the problem. Also changed the valve block but also still got the warning. Did anyone else have the issue, and find a different fix ? or is this a good place to start ? I guess I'm living on borrowed time with an old compressor - so will probably go ahead and change that out anyway as a preventative. (Rear air bags were changed out about a year ago and are new OEM).

What do you guys think ?

Thx
 
#2 ·
I have a 2006 RRS HSE. For the past two months it has been code, and I have noticed the rear left side will sink down to bump stop over 2-3 days when parked. This week, I was seeing suspension warning light come on, about 30 seconds after start up. Compressor will start - inflate the ride height to normal, but then stop with the chime and warning light and message in the dash saying "Suspension Fault, Normal Ride Height Only" . The first couple of times it did this, the error would go away after a restart. But now it is consistently staying on. Car still drives normally. I think my compressor is original (I need to pull the cover to see if it is Hitachi or AMK)- and I'm at 113K miles. California is not humid - so my desiccant maybe has longer life than in places like Florida.

I had a friend with a code reader pull the code - "C1A20 pressure increases too slow when filling reservoir". We looked at compressor temp - read 55C (30 seconds after start up) - not sure if that is normal or high (outside temp was 60F or so).

After reading the forums, it looks like desiccant in compressor drier degrades, clogs value block (hence the minor leak (I assume back into the reservoir because rear left valve sticks open just a little ?) - and the desiccant is also clogging the compressor inlet (?) which leads to the warning.

I saw a few posts where people had change the compressor (or rebuilt it) , but it didn't fix the problem. Also changed the valve block but also still got the warning. Did anyone else have the issue, and find a different fix ? or is this a good place to start ? I guess I'm living on borrowed time with an old compressor - so will probably go ahead and change that out anyway as a preventative. (Rear air bags were changed out about a year ago and are new OEM).

What do you guys think ?

Thx
did you also replace the exhaust valve spring?

https://www.ebay.com/itm/LAND-ROVER...IT-LR020590/163541858300?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
 
#3 ·
Didn't replace anything yet - I assume new compressor would come with new drier , exhaust valve etc. I guess I could just rebuilt , but at this age, perhaps better to replace the whole thing. Anyone have comments on Dunlop, versus Hitachi (maybe the same ?), versus OEM, versus the cheap o ones on eBay etc. ?
 
#5 ·
The primary cause of the fault will be the blocked desiccant - you can buy a complete kit that contains what is required, as well as replace the piston dealing ring and the exhaust valve. You will have desiccant dust certainly in the main valve block and this will need cleaning - however if it settling you well need to look at the other valve blocks or maybe a leak in the airbag on the corner that is dropping.

The compressor in that ebay link does not look like a genuine Hitachi (they are very hard to find now) it is most likely a chinese copy (termed Hitachi Type) - particularly at that cost - new genuine Hitachi compressors are more than twice the listed price.

If you are inclined buy the rebuild parts and rebuild, if not buy a new compressor - I am not sure if the quality of the chinese knockoffs of the AMK or Hitachi is OK - maybe OK - Dunlops have mixed reports so do your own research.
 
#7 ·
1. Old descant did not look too bad - and was not too powdery - filters might have been a bit clogged - but didn't;t look too bad.
2. Replaced piston ring and guide - old one also did not look bad
3. Replaced exhaust valve spring (and stopper) - again old one did not look damaged.

Connected everything back up - compressor works (as before) - but yellow warning light still comes on after ~1 min (+/-). The only difference now is - if I raise to off-road height immediately on start-up - that works no problem (before it worked, but I got a "suspension raising slowly"; warning). In off-road height - no warning light.

So, I think my compressor is good - however - perhaps the rear valve block (has a small leak back - i.e. sticking valve for left rear) - would that be enough to cause the C1A20 warning and compressor shut off after start up (and deflation of rear left spring after a few days when Parker) - (because the valve is sticking slightly open for that side - and when the compressor tries to pump to the tank - that open valve causes pressure to read low ? Or should I be looking somewhere else for a leak ? Thx
 
#8 ·
I have a 2006 RRS HSE. For the past two months it has been code, and I have noticed the rear left side will sink down to bump stop over 2-3 days when parked. This week, I was seeing suspension warning light come on, about 30 seconds after start up. Compressor will start - inflate the ride height to normal, but then stop with the chime and warning light and message in the dash saying "Suspension Fault, Normal Ride Height Only" . The first couple of times it did this, the error would go away after a restart. But now it is consistently staying on. Car still drives normally. I think my compressor is original (I need to pull the cover to see if it is Hitachi or AMK)- and I'm at 113K miles. California is not humid - so my desiccant maybe has longer life than in places like Florida.

I had a friend with a code reader pull the code - "C1A20 pressure increases too slow when filling reservoir". We looked at compressor temp - read 55C (30 seconds after start up) - not sure if that is normal or high (outside temp was 60F or so).
The error code gives you your answer your compressor is weak and not filling the air reservoir as fast as it should You will need to rebuild or replace.
 
#9 ·
You probably still have an air leak around the compressor somewhere - did you rebuild it correctly - did you reinstall the stainless steel reed valve at the top of the compressor cylinder the correct way - when you put the new exhaust valve in did you check it is correctly seating and the face it seats in is nor corroded or has dirt in it. This can cause in internal leak so no detectable by squirting the compressor with soapy water.

Did you check the desiccant chamber cap - they can leak between the two pipes. My was leaking at the exhaust valve and the cap and I replaced my cap with the metal cap and the leak stopped.

Did you pull the central valve block out and clean it all out - if it has internal leaks it can allow air out through the compressor and out the exhaust port - or a simple external air leak through a perished O ring but not likely. More likely to have desiccant dust in the internal stopping valves closing correctly (like the compressor exhaust valve). It is easy to pull apart and clean - just de-pressurise first.

Good luck with it.
 
#11 ·





BINGO ! I checked the end cap fittings with some soapy water - when the compressor was running - and yes there was an air leak from the red fitting. The X8R kits had a new billet aluminum end cap - so I took compressor out again (much faster this time), swapped the caps, reinstalled everything , and now it is all working with no lights !

Thanks to Garry from Aus ... owe you a stubby if you are ever in Silicon Valley ! Cheers - Mate
 
#21 ·
Hi all! I'm having exactly same issue with our 2007 LR3. Alpaca, if you were to do it all over again, knowing what you know now, how would you recommend I proceed? I have a pretty good notion, but asking seems like a good idea! I believe our compressor on this one (we have 2 LR3s) was replaced recently enough. Prior to this C1A20 error code--we have a iCarsoft reader--we were having slow deflation issue, but unclear from where/which tire.

All advise would be much appreciated!