Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
Quantifying Normal EAS Operation
Chock it up to being an engineer, or perhaps an anxious LR owner, I’ve been reading extensively on the EAS system in the Discovery 3 and 4. Among many things, there seems to be a lack of baseline for what “normal” operation for the system is. Said another way, there is no established range for how much suspension drop is reasonable over a time period nor how long a compressor should run in various states.
Based on reading many threads, I am led to believe normal function is as follows:
Approximately 1mm of suspension drop over a 24 hour period.
Ride height changes approximately 5 seconds (Access to normal, normal to off-road)
Air compressor run time of 30 seconds or less on cold start
Air compressor run time of 60-90 seconds during height changes
I’ve been trying to decide if I need to service my EAS, and have collected the following data. This data seems to fall between values I would deem as “high performing,” which is just a few mm suspension drop over a period of one week, and “urgent service needed” systems where the vehicle lands on bump stops overnight.
To gather this data I pulled fuse 26, and monitored over a period of 96 hours. One test was conducted from normal height and then I repeated for 96 hours beginning at off-road height. The results were the same, hence only summarized once below.
Compressor run time after 96 hours: 2:35.00 (min:sec)
Compressor run time after 12 hours 00:35:00 (min:sec)
Compressor run time from normal to off road height: 01:15.88
Ride height change from normal to off road height: 00:5.00
Compared to above, the rear is within normal operation tolerance. Air reservoir and compressor likewise respond to height changes and demand in normal times.
The front drop, which moderately exceeds 1mm/24 hours, is likely to have a leak in the front valve block or service line has a small leak. I know the blocks were rebuilt by a previous owner 2 years ago, so perhaps the replacement was faulty, or desiccant artifacts have migrated to the valve block seals.
The suspension drop is insignificant enough that I would leave it alone if not for my concern that doing so will continue to place an undue demand on the compressor and result in a failure. We drive the LR3 on average once a week when we go into the mountain side, so these minute pressure losses do compound over 4-7 days, placing high demands on the compressor. As it is, there are no suspension codes, even when compressor runs for 2.5 minutes.
Summary questions for the group:
What is an acceptable/normal ride height drop over 24 hours?
What is a on acceptable/normal air compressor run time upon cold start?
Should I work on my EAS system, or leave well enough alone?
If consensus says the normal operations are different than I have stated above, I will edit the values for future reference.
8th Nov 2021 4:46 pm
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10363
did the previous owner service the compressor ?
maybe that is what should be done. Service the beads (microwave them) and clean or replace the filter.
8th Nov 2021 6:10 pm
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
Great question, Pete. This made me confirm my assumptions and I’ve realized I made an error! Upon reviewing the vehicle listing again, the PO notes the compressor was overhauled (valves, o-rings, dryer) but not the blocks. Seems odd not to service the valve blocks as well, so I must have assumed that was included. This makes it even more likely the front block has some minor issue. I’ll order an o-ring kit and start there.
I am still curious about other owners opinions of “normal”, so as to give a baseline to anyone trying to decide if their system is just aged or truly in need of service.2008 LR3 HSE, 4.4L V8
8th Nov 2021 6:44 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
Re: Quantifying Normal EAS Operation
Yankee_Rover wrote:
What is an acceptable/normal ride height drop over 24 hours?
What is a on acceptable/normal air compressor run time upon cold start?
Should I work on my EAS system, or leave well enough alone?
Q 1. None! If the integrity of the system is ok there should be no loss in ride height. However, an aging
D3 will eventually begin to loose pressure at the air bags, if not elsewhere.
Q 2. Depends on what air is in reserve from the previous cycle, or if any has been lost due to a leak. If
the system is 100% tight, and the reservoir has been filled shortly before the last ign cycle ended.
The compressor will not need run on start up!
Q 3. Yes, you should! The compressor comes under the LR service schedule requiring the desiccant and
filters to be changed periodically. I tend to do them every three years or so as I am in a very high
humidity climate. In drier climates this can be extended but you may have to consider dust
ingress. It's simple stuff to do and will prolong the life of the compressor as well as the valve
blocks. yµ (idµ - eAµ) ψ=mψ
8th Nov 2021 6:58 pm
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
My o-ring rebuild kit arrived Saturday and we have a dry spell for a few days so I started the work of rebuilding my front valve block. I’ve gotten as far as opening my block and I think I found my problem —notice anything missing?
Yikes. I’m sure this is my problem, given the slow pace of my leak. If there were anything more missing I probably couldn’t keep enough pressure in the system to leave my drive.
Nonetheless, I’m going to carry on with the rebuild.
Edit: for anyone that hasn’t seen the inside of one of these blocks, there should be 3 large, orange o-ring seals in the channels which the screw driver is pointing.
Edit II: This valve block is fubar’d. The valves were seized (corroded) and a real bear to separate. After separating it’s clear this is an inferior knock-off part someone has replaced. The solenoids have no springs or orings, and the upper/bottom cylinder are glued together. It’s a wonder that the ride
heights ever worked on this thing —very likely this block didn’t do a thing and the front suspension pressure was being controlled by the central valve block. I’ll have to investigate the central and rear blocks another day to see if they are also knock offs. For now, I’m working on sourcing an original to rebuild or OEM part.
2008 LR3 HSE, 4.4L V8
16th Nov 2021 10:03 pm
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
Well after discovering the front valve block was a poor reproduction piece, I sourced a parts car takeoff and rebuilt that over the weekend. At this point the car had been sitting for 3 weeks, so I checked battery voltage with my DMM and it registered at 11.7V so I read up on charger here and settled on a CTEK MST 5.0. Charged the battery yesterday, and once at step 7 this morning I started the car up for the first time in weeks.
It was a minor disaster. Car raised and then nothing. Suspension dash light comes on and I feel immediate disappointment. I get out to inspect and find the electric connection block dangling, despite my best efforts to seat it (and hearing it ‘click’ all the way). Luckily I had left the fender flare off so I was just able to access the connector for a new attempt. Eventually I got it to click and not pull off when I gave it a tug.
Cleared the code with my GAP tool and drove off to work. About 20 minutes into my drive, I get another Suspension fault. At this point I assumed my connector had popped off again, but my height was stable so I continued the 10 minutes to my office. Once in the garage I ran the codes again and have a new one, C1130-66(AF) Frequent Level Activity in the up direction or unable to lift.
I was able to raise the car to off road height, so it is able to lift. Then I shut the engine off and did a walk around. I could hear air leaking from the front valve block area (which is presently all buttoned up). I’ll have to pull the mouldings off when I get home and try to identify the leak with soapy water. I’m assuming it’s one of the Voss connectors I reused, may need new o-rings for those. Hopefully the block is solid, it was rebuilt with new o-rings and I did not see any cracks.
I’ve gone from a very minor leak to a very noticeable one. Frustrated but not defeated!2008 LR3 HSE, 4.4L V8
24th Nov 2021 4:32 pm
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10363
When the 3 tiny round seals are missing from inside, it causes the connector to blow off
24th Nov 2021 7:17 pm
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
I did not have any O-rings leftover after the rebuild (I used fresh rings from a kit), but I can confirm that on one of the failed attempts to seat the connector it seemed to eject as if a puff of air shot it off. I thought it was my imagination. This seems related to my leak.
I’m assuming from your description this isn’t one of the large, orange rings between the body halves, but rather one of the smaller ones seated on the corner valves? A picture being worth a thousand words, could you suggest if it might be ring A, B, C, or D (below) I want to inspect?
2008 LR3 HSE, 4.4L V8
24th Nov 2021 7:42 pm
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10363
Check A
24th Nov 2021 8:59 pm
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
Alright, this has gotten more interesting and may warrant its own thread if found not to be related.
Upon startup for the drive home I got a Suspension fault, however it was triggered by 3 new faults: Front right ride sensor. This was accompanied by two additional faults for each front EAS corner valve (left and right). These fault codes were unable to be cleared by the GAP IID tool, and would reappear immediately after clearing. Next step was to confirm the valve plug was still connected. I managed to remove the fender flare with my nails (never leaving home without my tool bag again, even for a city trip), and could verify the valve body connection plug was properly seated. On to more invasive fixes…
I next attempted to override the EAS system by using the GAP IID procedure, IIDTool Menu->Service Test->Suspension->Test Valve->Adjust Front, adjust to the desired height. Supposedly this works when you have broken sensors and, to a lesser extent, broken struts. However, no dice in my situation. The compressor would kick on for a split second and the EAS fault would flicker yellow, then turn to red, and prevent the procedure from initializing. I think the valve block faults were preventing the procedure from working. The air compressor did run for 15-30 seconds a few odd times outside of this GAP IID dance I was doing, but I could never trigger it myself. It always happened when I was outside the vehicle trying to inspect something else.
Out of any other options, I was between calling a tow truck on a holiday weekend or limping home. Based on reading some quick tales of other LR owners limping for 30 miles and more with similar or worse problems, I opted for the limp. 17 miles and 1 hour later, I arrived home.
I’ve pulled the front valve block out to tear down this evening. Hopefully the issue is obvious once it is apart.2008 LR3 HSE, 4.4L V8
25th Nov 2021 1:45 am
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
Valve block disassembled. It appears one of the large o-rings migrated when the valves were joined, allowing for an air loss. I inspected the external o-rings of each valve and all appeared proper. The crushed o-ring was replaced with a fresh spare and the block assembly reinstalled.
Upon startup I was able to clear the control valve codes. Only two faults remain:
Suspension: C1A04-1C(AF) - Front right height sensor
Transfer Case: U0132-86(2F) - Lost Communication with Ride Height Control Module
I attempted to do the ride height override again, using the procedure noted above. I was able to raise and lower the rear axle, but the front axle would not articulate though the compressor would run. I also tried to raise the front left and front right corners separately, but got no movement despite the air compressor running.
Thoughts on if the valve block is still problematic, or perhaps the block is now fine and a single sensor has gone faulty? I wonder if dropping to the bump stops was the final straw for this sensor.
Edit: Based on significant reading on the site, I’m going to focus my efforts on the height sensor. The lost communication code is likely a result of the sensor fault, and not the cause. I found the following diagnostics and symptoms checklist, so I’ll start with that. I’ll use the GAP tool to pull live data of the sensors and hopefully have more to go on.
Click image to enlarge
2008 LR3 HSE, 4.4L V8
25th Nov 2021 3:26 am
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
I’m continuing to research this issue and I welcome any insight. My goal is to have a list of things to troubleshoot in a logical manor here is what I’ve got:
-Determine FR ride height sensor status:
-Engine off, ignition off: Check wiring for continuity between plug (C1697) and first connector (C3010, behind headlight?)
-Engine off, ignition on: Confirm ground at plug (C1697-5), confirm 5V supply at plug (C1697-1)
If continuity, ground and 5V supply are good, wiring is OK. Proceed to sensor check:
-Engine off, ignition on: check live values on sensor with GAP —this will check the Signal wire (C1697-4). Height sensors should give a value between .5-4.5V, outside this range is faulty.
If the wiring and sensor are fine, then I’m hosed
Here’s a wild card: I’ve been reading about EAS diagnostics and there are all sorts of situations that will cause ride height control lockout. My rear axle is at off road height and the front axle is on the bump stops. I think this is a situation will prevent articulation, however, is this a lockout that not even the GAP tool can override?
I have the ability to lower the rear axle with GAP using the test valves function. My last resort may be to lower the rear axle to bump stops and then attempt to clear the fault again, then raise the car.
Click image to enlarge
2008 LR3 HSE, 4.4L V8
26th Nov 2021 12:16 am
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
Had to take a break from this while I got a better Digital Multi Meter and updated GAP IID tool. I’ve been able to take the following readings today with the Gap tool, I’ll have to wait until the weekend to do any in depth work with the DMM.
Based on the 0 V signal from the front right height sensor it is clear that it is indeed an issue. However, I’m not sure this indicates the sensor itself is faulty. It seems there could still be a wiring fault either preventing the sensor from receiving the 5V supply power or interrupting the signal return.
To test the supply power and ground at the sensor, I think I can remove the sensor and test off of the plug directly. Any thoughts on how to test the return signal?
Also, I again tried to override the height sensor by using the test valves feature in Gap to raise the vehicle. I could raise the rear immediately, but the front wouldn’t budge (tested for 10 seconds or so). I thought the Gap tool overrides height controls in this procedure —am I misunderstanding, or does it demonstrate there is still a valve block issue?
Thank you all for any advice.2008 LR3 HSE, 4.4L V8
9th Dec 2021 2:49 am
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10363
Click image to enlarge
I would say its a fault with the supply to the sensor, or the sensor has failed internally.
I glean this as you have a 4.95v reading on the supply to that sensor.
The sensor isn't pulling the supply voltage down a little, like the others, either due to internal failure, or break in the supply wire +.
As you say, disconnect the sensor, (ensuring you have axel stands etc. in place and aren't going to get crushed if the air suspension decides it wants to suddenly change) and measure the supply pins and see if you can get approx. 5v
9th Dec 2021 1:00 pm
Yankee_Rover
Member Since: 02 Jun 2021
Location: Seattle
Posts: 183
Much appreciated, Pete. I believe I have diagnosed two problems, hence the odd behavior.
First, I’ve confirmed I have installed a Rear Valve Block (RVH000055) in the front position (RVH000095). When comparing the rebuilt replacement with the removed knockoff, they appear the same. The front and rear valve blocks are nearly identical, however the control valves are reversed on each part. Paradoxically, the wiring and air supply lines are also reversed, so while the parts should be interchangeable, there must another reason they have different part numbers. I will replace to remove all doubt.
Secondly, it appears I’ve had my Right Front sensor go faulty. I’ve confirmed supply power reaches the sensor, and that there is ground at the sensor. Test for continuity between the fly lead at the sensor and the next circuit plug (behind the headlight) is positive, which should mean the return signal would be returned to the control module if it were being sent. This only leaves an issue with the sensor. It seems odd that this would present immediately after the valve block issue, but perhaps the articulation of running to bump stops finally did the sensor in.
I’ll be ordering the proper valve block and sensor, and then update this thread with my findings once installed. Yesh, this got expensive quickly!
**This post is edited because I’ve had time to do more diagnostics and my previous hypothesis in this post, while creative and interesting, was woefully incorrect.**2008 LR3 HSE, 4.4L V8
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