ALB_LR3/4 · Jan 3, 2020

Hi there,
- At the moment the suspension has not moved from the bumps stops. With the old pump the fronts lowered, but I put this down to the drier end cap leaking like a sieve. I did not notice any lowering when I had things working a little better.
- I did not get a new relay with the pump. I have swapped with the engine management relay and it seemed okay. The EAS relay started the engine.
- There was some silica dust but not a lot. I stripped down the reservoir relief valve close to the pump and found a small amount of white silica dust. The biggest build up was by the pressure sensor. The wiring seemed intact, but I wonder what impact it would have if the sensor is not reading correctly?
- I will check tomorrow to see if the valve blocks are opening. The motor temperature is within range and the pump will shut off. The compressor temp is not reading and shows 9.0c
- I have been testing the system with the bonnet up. Would this stop the suspension from raising?
- At various times I have had the two pipes from the rear of the compressor connected. The 6mm air intake is currently connected and the exhaust is disconnected at the connector I added 2" from the connection to the pump. Other than making it easier to hear what the exhaust valve is doing I can reconnect it. Is there a downside to running with it disconnected?

ALB_LR3/4 · Jan 3, 2020

No audible or visible air leaks.
I am familiar with the normal hiss from the compressor. It is not doing this. The solenoid is being fed a small signal not sufficient to open it fully. I have tested this with the solenoid from the old pump removed so I can see what is happening. When you hear the typical hiss the solenoid opens fully with a clunk. Both solenoids are doing the same: high pitch whine and you can see the pilot exhaust is slightly open. With the new one on the pump this resulted in small soft bursts of air with the occasional hiss.

gstuart · Jan 3, 2020

ALB_LR3/4 said:
Hi there,
- At the moment the suspension has not moved from the bumps stops. With the old pump the fronts lowered, but I put this down to the drier end cap leaking like a sieve. I did not notice any lowering when I had things working a little better.
- I did not get a new relay with the pump. I have swapped with the engine management relay and it seemed okay. The EAS relay started the engine.
- There was some silica dust but not a lot. I stripped down the reservoir relief valve close to the pump and found a small amount of white silica dust. The biggest build up was by the pressure sensor. The wiring seemed intact, but I wonder what impact it would have if the sensor is not reading correctly?
- I will check tomorrow to see if the valve blocks are opening. The motor temperature is within range and the pump will shut off. The compressor temp is not reading and shows 9.0c
- I have been testing the system with the bonnet up. Would this stop the suspension from raising?
- At various times I have had the two pipes from the rear of the compressor connected. The 6mm air intake is currently connected and the exhaust is disconnected at the connector I added 2" from the connection to the pump. Other than making it easier to hear what the exhaust valve is doing I can reconnect it. Is there a downside to running with it disconnected?

hiya

at last round the sheet I was looking for ref ur fault code

Indeed having the bonnet open can stop the suspension moving , however on other times suspension has moved, on mine m very bizarre

no problems having those pipes off , plus u now have a brand new hitachi

to save u going round the bend , sit in the disco with ur gap iid connected , assume u use either an iPhone or iPad

Select the live data values for u suspension system, ur be able to see with the engine running if any valve blocks are opening and u can watch what the entire sustenances is doing

do some screen shots or I can send the results to ur email

When the engine is off watch the air pressure , it should drop according to the pressure chart

Here’s also the chart I finally found

gstuart · Jan 3, 2020

ALB_LR3/4 said:
No audible or visible air leaks.
I am familiar with the normal hiss from the compressor. It is not doing this. The solenoid is being fed a small signal not sufficient to open it fully. I have tested this with the solenoid from the old pump removed so I can see what is happening. When you hear the typical hiss the solenoid opens fully with a clunk. Both solenoids are doing the same: high pitch whine and you can see the pilot exhaust is slightly open. With the new one on the pump this resulted in small soft bursts of air with the occasional hiss.

thks , leave that with me and I’ll do some digging for u

Have u watched it also via the iid to see what % the exhaust valve is opening

so we don’t go all over the place , I’ll find some more info for u regarding that

ps, are the earths ok around the valve block , compressor , inc continuity test

thks for the replies and will get back to u as soon as I find some details

ALB_LR3/4 · Jan 3, 2020

Which is the gallery pipe?
Is there a test for the pressure sensor?
I will take some screenshots tomorrow evening.

gstuart · Jan 3, 2020

One test as this is bugging me , if u have a jump lead to imitate an earth, put one end on the compressor and another of the chassis or air tank please

my brain is ticking away with this and abit like a dog with a bone

as the ecu uses an earth signal and wondering if there’s a stray current

am just going through all my manuals , also if u haven’t got a full workshop manual I can send u a link via a pm

ALB_LR3/4 · Jan 3, 2020

I didn't think to check what % the exhaust valve is opening. I will do so the next time.
I will also check the earths. I think I read that the solenoid is sent an earth signal to trigger the exhaust. It does seem like it is an electrical fault.

gstuart · Jan 3, 2020

ALB_LR3/4 said:
Which is the gallery pipe?
Is there a test for the pressure sensor?
I will take some screenshots tomorrow evening.

hiya

the gallery pressure is basically the whole of the pipe system, as in what the whole system contains

I’ve seen the test for the pressure sensor, I’ll find it for u

cheers and hopefully between us all should be able to pin it down, inc saving u a fortune from those rip off JLR dealers

gstuart · Jan 3, 2020

ALB_LR3/4 said:
I didn't think to check what % the exhaust valve is opening. I will do so the next time.
I will also check the earths. I think I read that the solenoid is sent an earth signal to trigger the exhaust. It does seem like it is an electrical fault.

doesn’t help me gassing , lol

indeed that’s the way I’m also thinking ref the electrical error , I had a sod of a job with mine on the electrical side, ended up with a multimeter and doing a continuity test on every single wire, from front to back, connectors to the ecu

was a few dirty earth connections , that why I though using a jump lead or wire with some crocodile clips to simulate an earth

might have to do a continuity test from the ecu to the connectors at the reservoir valve block / compressor

but indeed let me find some details for u ref the pressure sensor and see what u come up with screen shots etc

hopefully that helps a little

Ps, how many hours behind are u from GMT please

ALB_LR3/4 · Jan 3, 2020

I will test for a stray current. This could account for the solenoid being live but with insufficient voltage to open fully. I really appreciate all of the help and a PM to the full workshop manual would be appreciated. I may already have it as I did download one previously, but I am not sure it is comprehensive. It is midnight here in Edmonton and I have to be up and out to work early. I will get back at it tomorrow evening.

gstuart · Jan 3, 2020

ALB_LR3/4 said:
I will test for a stray current. This could account for the solenoid being live but with insufficient voltage to open fully. I really appreciate all of the help and a PM to the full workshop manual would be appreciated. I may already have it as I did download one previously, but I am not sure it is comprehensive. It is midnight here in Edmonton and I have to be up and out to work early. I will get back at it tomorrow evening.

ur so welcome and we all try and help each other as much as we can

u want connector number 3 , as per pic and indeed if u do some continuity tests / voltage drop between the relevant wires , in the mean time I’ll do some more digging for u

Many thks, so ur 7 x hours behind us

I’ll send a pm for u

know you’ve seen these but thought if I lost them here it will be easier than having to go back and forth seeing we’re dealing with electrics

gstuart · Jan 3, 2020

In the mean time I found where the connectors are located , alas included both sides to cover both bases so to speak of urs being LHD

gstuart · Jan 3, 2020

Included the connectors so easier for u print print out

gstuart · Jan 3, 2020

Also when u use ur iid please check the software is correct for hitachi plse

thks

gstuart · Jan 3, 2020

Thought it would make life easier having the wiring diagrams here

see the pressure sensor reqs 5 Vdc

Still digging about the exhaust valve

gstuart · Jan 3, 2020

Double post

ALB_LR3/4 · Jan 4, 2020

Late home from work, but managed to get an hour in the garage and made some progress in the right direction hopefully. I am feeling more confident that this is an electrical issue.

If I am correct in thinking the pilot exhaust valve is triggered by a ground signal this is what I have found:
1. The positive feed to the pilot exhaust valve is live with 12v when triggered by the door opening, ignition on or engine running. I verified this as showing 12v between the BW pos wire and the chassis after opening the door.
2. In the wiring plug at the compressor there was a reading of 3v+ between the pos and neg feed for the pilot exhaust solenoid.
3. When I connect the old solenoid to the feed from the pos and neg at the plug it is making a high pitch noise, is held permanently open (partially open) and is receiving 3.94v. If I am right about the ground trigger to open the exhaust when needed, having this constant voltage applied accounts the pressure is not building or releasing when expected.
4. To test the theory further I disconnected the negative lead from the solenoid and touched it to a vehicle ground. I got a reading of 12v and the solenoid opened with the expected clunk.
5. I reconnected to the pump with the ignition on the Gap iid connected and before it dropped a fault the exhaust was at 100%. This would be partial but would accont for the slow build up of pressure.
6. I disconnected the plug behind the headlight and connected the ground and earth feed to the solenoid. I could not get it to recreate the fault by the compressor
7. Just to eliminate it as a fault I checked the continuity to the pos/neg feeds from the control module in the drivers footwell.

Saturday's jobs:
Test between the pos and neg at the control module and see if there is a constant 3-4v.
Strip the plug that connects to the compressor and look for issues
Trace between the control module and the plug looking for faults.

As it is the only thing that has been disturbed in the process of taking the old and new compressors on and off quite a few times, I am thinking it may be the plug. This is not something I have come across before but perhaps there is a partial ground being made in the plug.

The picture is my test rig. The solenoid is open and humming, even though at this angle it looks closed.

gstuart · Jan 4, 2020

ALB_LR3/4 said:
Late home from work, but managed to get an hour in the garage and made some progress in the right direction hopefully. I am feeling more confident that this is an electrical issue.

If I am correct in thinking the pilot exhaust valve is triggered by a ground signal this is what I have found:
1. The positive feed to the pilot exhaust valve is live with 12v when triggered by the door opening, ignition on or engine running. I verified this as showing 12v between the BW pos wire and the chassis after opening the door.
2. In the wiring plug at the compressor there was a reading of 3v+ between the pos and neg feed for the pilot exhaust solenoid.
3. When I connect the old solenoid to the feed from the pos and neg at the plug it is making a high pitch noise, is held permanently open (partially open) and is receiving 3.94v. If I am right about the ground trigger to open the exhaust when needed, having this constant voltage applied accounts the pressure is not building or releasing when expected.
4. To test the theory further I disconnected the negative lead from the solenoid and touched it to a vehicle ground. I got a reading of 12v and the solenoid opened with the expected clunk.
5. I reconnected to the pump with the ignition on the Gap iid connected and before it dropped a fault the exhaust was at 100%. This would be partial but would accont for the slow build up of pressure.
6. I disconnected the plug behind the headlight and connected the ground and earth feed to the solenoid. I could not get it to recreate the fault by the compressor
7. Just to eliminate it as a fault I checked the continuity to the pos/neg feeds from the control module in the drivers footwell.

Saturday's jobs:
Test between the pos and neg at the control module and see if there is a constant 3-4v.
Strip the plug that connects to the compressor and look for issues
Trace between the control module and the plug looking for faults.

As it is the only thing that has been disturbed in the process of taking the old and new compressors on and off quite a few times, I am thinking it may be the plug. This is not something I have come across before but perhaps there is a partial ground being made in the plug.

The picture is my test rig. The solenoid is open and humming, even though at this angle it looks closed.
View attachment 197527

hi

some great progress made there and don’t faint I understand it as u explained it extremely well

indeed that ground seems the issue, that why I wondered ref usinf a temp ground lead but by u grounding it on the chassis does the same thing

maybe it’s something as simple as a bad connection at the ecu causing the ground issue

great work and plse keep us updated and can imagine when you’ve found it will be the eurika moment

have been searching more and more ref that solonoid and can’t find any more info apart from hst you’ve found

Look forward to the update

gstuart · Jan 4, 2020

May i ask, is there any writing on that solonoid please , thk

plus there some ground in the front footwells where the suspension is fitted , think it will be ur passenger side ??

ALB_LR3/4 · Jan 5, 2020

Another day with a few false starts but no resolution.
No writing on the solenoid and on the LHD model it is on the driver side A-pillar.
I did manage to raise the suspension, but the exhaust vent solenoid is powering up at 3.7 - 3.9v. When driving I can see the exhaust valve open at 100% for around 8 seconds before I hear it release. In the garage, I can see it doing the same. I am also not getting a reading on the compressor temp. This results in the occasional fault code.
When the problem started I reset the suspension calibration to default which I believe is the first recorded reading when registered with the GAP iid.
When the suspension raised to standard the front is at 20" from wheel centre and the rear is at 18". I will follow the guided calibration routine tomorrow and see if that makes a difference. I do not have any fault codes for the ride height sensors and I am not sure that would account for the solenoid being partially grounded.
While sick of the site of it, I think I could remove the compressor in my sleep lol.

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