D3 suspension fault nightmare, need help

[Iherbst87]

Hey all. I'm having faults with my suspension again. Right rear height sensor fault, along with invalid data sent from ride level control module fault in the TCCM. The right rear sensor has been replaced twice and i did a calibration, i replaced with wiring from the sensor to the air suspension ecu, pulled the tccm out and all the pics are nice and clean, i did find some small corrosion inside the transfer case control module, cleaned it up and seemed to have been ok, but comes on more and more now with the same faults. All readings to and from the sensor and the eas is fine with no breaks in readings. Can anyone shed some light on this by any chance?179289

[Graeme]

Did you find any corrosion on the TCCM contacts? If so then the connector pins will have to be cleaned too, best done by removing them from the shells. Sometimes the TCCM pcb is irreparably damaged by corrosion.
However a canbus fault at the TCCM will cause every downstream module to post faults so unlikely a fault with the TCCM.

The suspension module may be faulty if the fault can't be triggered by wriggling the wires at the rear harness connector at the suspension ecu.

[Iherbst87]

Hi Graeme,

No i didn't find any corrosion at any pins anywhere, only at one spot inside the ecu. Ill try put up a photo. I have an Autel and can see all the live data, all the sensors are moving as they should, voltages moving up and down, even a graph shows them moving well with no breakes. 179290

[Eric SDV6SE]

When was the last time you checked the compressor and its dessicant?

[Graeme]

TCCM pin corrosion is normally the issue when moisture gets in.

I would try to cause the fault by wriggling the wires in the forward-most connector on the suspension module while the ignition is switched on, including flexing the connector socket a little. You probably already know that that connector is the rear harness connector and includes the canbus pair.

[DiscoDB]

That corrosion on the ECU pins looks bad to me. A bit of moisture and easy to imagine this is causing intermittent faults.

[Iherbst87]

Thanks for the reply guys. I changed the compressor desiccant and changed the compressor completely and made no difference.

Graeme, i have tried to wriggle all the wiring at all the connectors while stationary, ignition on and running, but nothing comes up. It only faults once over a few kms/h, and being a mechanic learning more about landies, is driving me nuts.

Yes that corrosion did seem to be nothing, i cleaned it up and flowed the solder on pretty much every accessible spot i could, and still no change. I live about 5 hours from the nearest place to get a part just to 'try' so unfortunately thats out the question at the moment. Do you guys think i am missing something before ordering another transfer case module, or is it maybe the eas module playing up?

[DiscoDB]

When you mentioned you can see the live values moving as expected, is the left and right rear giving different values or are they always identical? (They should be different).

Does sound like damaged wiring, or a bad connection, or a bad splice somewhere. The TCCM could also be damaged if any of those corroded pins did create a short.

[Graeme]

That corrosion on the ECU pins looks bad to me. A bit of moisture and easy to imagine this is causing intermittent faults.There's certainly a lot of rubbish between the legs.

[PeterOZ]

Hi Graeme,

No i didn't find any corrosion at any pins anywhere, only at one spot inside the ecu. Ill try put up a photo. I have an Autel and can see all the live data, all the sensors are moving as they should, voltages moving up and down, even a graph shows them moving well with no breakes. 179290


You will be getting dendrites within that corrosion which can cause erratic operation. See if you can clean those up with isopropyl alcohol.

[shanegtr]

Can you do a data log with the Autel? Might be able to pin point what is going on at the point of the fault being triggered. Might be something your not seeing while the vehicle is stationary.

[Iherbst87]

There was a fair bit there yes, until i cleaned it all up.

Yes i did a full data log with the Autel, graphed it and there was nothing to show a fault or drop or rise or break or anything, it all performed perfectly, including the rears moving independently of eachother.

Disco DB, do you know where i can get a wiring diagram for the communication between the eas ecu and tcm? I have the wiring diagram for the sensors to eas and switches.

Recap, the fault codes are as follows, cycle the ignition and goes to this179307

[DiscoDB]

The D3 workshop manual at the AULRO shop has the wiring diagrams.

[Graeme]

Recap, the fault codes are as follows, cycle the ignition and goes to this179307
When do the faults return after having been cleared - within seconds or after a drive?

Edit: I see from your 1st post that it only faults once over a few kms/h. I'm favouring a faulty suspension module.

[Iherbst87]

Thanks Disco DB, ill have a look, still learing how to use the forum.

It can happen 10m up the road, or 10km, whenever it wants too. Sometimes it never happens until i go on a gravel road above say 15km/h

[Graeme]

Have you checked for chafing of the harness that runs along the chassis in from the left front wheel? Its retaining clip can break allowing the harness to be rubbed by the inside of the tyre on left turns which can cause short and open circuits in the height sensor and ABS circuits.

[Iherbst87]

I have had a quick look at them, but no rubbing or anything that i could see, i was more concentrating on the rhr harness section

[BradC]

The D3 workshop manual at the AULRO shop has the wiring diagrams.

https://www.aulro.com/afvb/l319-discovery-3-and-4-a/285102-later-d3-wiring-diagrams.html?285102=#post3075498

[DazzaTD5]

If that first pic by the OP is of the TCCM then I'd swap it out for another, you are likely to continue to have **** with it until its replaced. its a oh so common issue on a D3 due to its stupid location.

As a side note, you can use a second hand unit if you feel the need and it wont need to be calibrated.

[discorevy]

If that first pic by the OP is of the TCCM then I'd swap it out for another, you are likely to continue to have **** with it until its replaced. its a oh so common issue on a D3 due to its stupid location.

As a side note, you can use a second hand unit if you feel the need and it wont need to be calibrated.

Hey Daz, I gave the O.P. your number to get a TCCM from you about 3 weeks back,
I believe he tried to contact you, have you still got some new ones there?.

G'day Ian:thumbsup:

[Iherbst87]

G'day Daz. Yeah still trying to source one locally to test before i buy a new one, but can you please let me know a price for a TCCM if you have one? Cheers

Heya Discorevy, long time no speak haha. Yeah still playing with the thing and still druving me mad with a BING evrry time its driven.

On a side note, i contacted the previous shop who used to look after this thing, and some of the last notes about suspension was a fault code for the right rear strut not filling or something like that, he said that the right rear air strut may have a leak under driving conditions and bumps pressure causing it to drop and maybe ecu thinks the sensor is faulty. Odd thing is it doesn't lower over night or anything that i have found. Have you guys heard of a fault like that before with an air spring? I suppose i could swap the air springs over left to right and see if the fault moves to the other wheel. Im still not rulling the TCCM out just yet either

[discorevy]

G'day Daz. Yeah still trying to source one locally to test before i buy a new one, but can you please let me know a price for a TCCM if you have one? Cheers

Heya Discorevy, long time no speak haha. Yeah still playing with the thing and still druving me mad with a BING evrry time its driven.

On a side note, i contacted the previous shop who used to look after this thing, and some of the last notes about suspension was a fault code for the right rear strut not filling or something like that, he said that the right rear air strut may have a leak under driving conditions and bumps pressure causing it to drop and maybe ecu thinks the sensor is faulty. Odd thing is it doesn't lower over night or anything that i have found. Have you guys heard of a fault like that before with an air spring? I suppose i could swap the air springs over left to right and see if the fault moves to the other wheel. Im still not rulling the TCCM out just yet either

Have a look at the valve block if you haven't already, could be blocking / sticking with old dessicant

[Iherbst87]

Have a look at the valve block if you haven't already, could be blocking / sticking with old dessicant

I did swap the valve blocks front to rear with no change, i also noticed the valve block which was on the rear (now in the front) was a new aftermarket one. I also inspected the lines on the rear air bags.

[Iherbst87]

So heres another test i did last night. I put the vehicle into offroad height, did all the measurements and locked the car, about 2 hours later i forgot to pull the 5A fuse to stop auto levelling. This morning i found 3 corners had lowered a bit, and the rhr was still the same ( measurements are at home and forgot to put them in my phone ). Any ideas? Maybe that rhr aur strut is leaking and the rest are lowering to suit the rhr?
EDIT: The rhr measurement was about 18mm lower than the lhr, and about 10ish mm lower then the fronts from memory.

[Graeme]

The fuse to remove to prevent lowering is the 20A suspension fuse in the engine bay fuse box. The 5A in the engine bay box is only a sense for the compressor relay contacts closed and the 5A in the passenger compartment fuse panel is the ignition sense.

[BradC]

I did swap the valve blocks front to rear with no change, i also noticed the valve block which was on the rear (now in the front) was a new aftermarket one. I also inspected the lines on the rear air bags.

Just a warning, but the valve blocks are not the same. The book says :

"The front and rear axle valve blocks are similar in their
design and construction and controls air supply and
distribution to the front or rear pair of air spring damper
modules respectively.

The difference between the two valve blocks is the
connections from the valve block to the left and right
hand air spring damper modules and the valve sizes.
It is important that the correct valve block is fitted to
the correct axle, otherwise leveling will be impaired due
to the different valve sizing.

Fitting valve blocks incorrectly would not actually stop
the air suspension from functioning. But will result in
slow raise and lower times and uneven raising and
lowering between the front and rear axles. "

So if you are chasing a fault, swapping blocks might not be the way to go.

[Iherbst87]

Thank you BradC. I checked the part numbers online before i did it and found them to be the same part number. Odd thing is it didn't change anything when i did swap them over, still had the same fault. I did open them both up to inspect and they had the same sized valves and seals. Hmmm, still something to think about too.

[PerthDisco]

Just a warning, but the valve blocks are not the same. The book says :

"The front and rear axle valve blocks are similar in their
design and construction and controls air supply and
distribution to the front or rear pair of air spring damper
modules respectively.

The difference between the two valve blocks is the
connections from the valve block to the left and right
hand air spring damper modules and the valve sizes.
It is important that the correct valve block is fitted to
the correct axle, otherwise leveling will be impaired due
to the different valve sizing.

Fitting valve blocks incorrectly would not actually stop
the air suspension from functioning. But will result in
slow raise and lower times and uneven raising and
lowering between the front and rear axles. "

So if you are chasing a fault, swapping blocks might not be the way to go.

Accessing and removing the rear block is a major achievement very very fiddly and need to be super careful not to cross thread on the plastic side

[BradC]

Thank you BradC. I checked the part numbers online before i did it and found them to be the same part number. Odd thing is it didn't change anything when i did swap them over, still had the same fault. I did open them both up to inspect and they had the same sized valves and seals. Hmmm, still something to think about too.

Are you sure? My copy of Microcat shows :
Front Valve block : RVH000095
Center valve block : RVH000046
Rear valve block : RVH000055

[Iherbst87]

BradC im not sure where i got my info back then, so looks like im swapping them back, thank you for the info again, will see how it goes again after the swap back. Being an after market one that was fitted, there might be an issue with it.

PerthDisco, yeah i noticed they were a bit fiddly for the back on, not too hard tho

[BradC]

F26 under the bonnet is the one you want to pop out in the D3. 3rd mini-fuse from the bottom on the right. That supplies power to the valve blocks, so pulling that stops the car self leveling.

I'd also check the part numbers on your valve blocks. If the rear had been replaced, it'd be worth checking it was replaced with the correct unit.

The faults did indicate an intermittent issue with the height sensor, so it may not be valve related at all.

[Iherbst87]

Yip will double check the part numbers.

Yeah thats right, thats whats giving me grief, so was aiming towards electrical somewhere. Still not sure what avenue i need to head in

[Flemington08disco]

Hi I had similar issues on my D3. After replacing compressor and all sorts of other things it ended up being a bad starter motor that was throwing faults through the whole system.
Since replacing I have had no suspension faults.




Hey all. I'm having faults with my suspension again. Right rear height sensor fault, along with invalid data sent from ride level control module fault in the TCCM. The right rear sensor has been replaced twice and i did a calibration, i replaced with wiring from the sensor to the air suspension ecu, pulled the tccm out and all the pics are nice and clean, i did find some small corrosion inside the transfer case control module, cleaned it up and seemed to have been ok, but comes on more and more now with the same faults. All readings to and from the sensor and the eas is fine with no breaks in readings. Can anyone shed some light on this by any chance?179289

[Iherbst87]

Thats a different one.

So heres a new thing i found this morning. So, if i put the vehicle into offroad height for about 3seconds before i leave the house or a parking lot, then lower it to normal ride height, it doesn't fault, like as in at all. The car can be stationary for a few hours or even 1 minute. So what now? Im really confused.
(I still have not swapped the valve blocks back)

[Iherbst87]

UPDATE TIME!!

So at this point i want to thank everyone for their input on this issue. It seems as though it has been resolved.

Apologies for the long winded post, so grab a drink and read up if you wish...

So from start to finish here it goes:
I bought the car from Perth and was informed the compressor was getting tired as it was about 9 years old, whicis fair enough, on the way home (400km) the suspension light came on, pulled over and cycled the ignition ignition, light gone for a few days. Then the light came on heading to do a 4wd recovery in Albany (yes we get calls from RAC for recoveries), it did it about 6 times in a 600m track and on the beach, anywho got to work and scanned the codes, found Right Rear height sensor code, contacted a landrover indie and guided me to diagnose the sensor, found the sensor was floppy, so replaced the sensor, struggled to do a calibration but got there. Drove around and fault came straight back on. Checked wiring and all connections, all ok. Got a GAP tool and scanned code, had RHR height sensor component failure, ordered another one under warranty and replaced. At this point i had also ordered and replaced the dessicant in the AMK compressor, and wow what a difference in build up pressure it made, but Surprisingly the light came back on. After a bit of to and fro convo's with my indie, we suggested replace the wiring to the ecu, did that and wham, no light for a day or so. Light came back on, then decided to swap the front and rear valve blocks (the rear valve block looked only a few months old too and an aftermarket one at that), SO at this point i should have checked the lines and connections. Carrying on and starting to find wiring diagrams, YouTube videos etc and not getting very far, i swapped the compressor for a known good one from my uncles D4, i checked the TCCM, slight corrosion internally, but cleaned and flowed the solder, did the same with the Air suspension ECU and still faulted. I even swapped the TCCM with my bosses RR sport, and made no difference. The light could always come on at total random. I contacted the previous indie in oerth who looked after the vehicle suggested a leak on the RHR air strut, so did a leak check over night and no leak, pulled the line off the air bag and everything looked good. Did a bit more looking at CAN wiring and connections just for shiggles and all ok. I decided to swap my compressor back at this point too. I got an Autel AP200 and always watched the values on the rear struts and no changes, spikes or drops when driving, but always rhr sensor fault at random. So as discussed on here recently i found out the front and rear valves are different, so decided to finally switch them back (on paternity leave now so have a bit of time up my sleave to work on it during the day), pulled the front valve block out, pulled the rear one out and bam, found the hose coming from the rear valve block to the rhr air strut was not seated on the brass split olive properly (I'll put the photo up) and at this point i had a sigh of relief, and nerves were shot as i wasn't holding my breath. Anyways i put olive back to its original position, and put it all back together. Started the car as normal, cleared the codes and drove it in a vacant block out the back, tried offroad suspension, flying in normal mode and even rock crawling in low range, no fault whatsoever. I drove around town this morning and no fault. SUCCESS AT LAST. So driving today i was always expecting to see fault come up, but finding it odd that its fine 🙂

Thanks again for reading, if you got this far anyways.

Photo of said culprit

179415

[Eric SDV6SE]

Well done, good result.

[BradC]

found the hose coming from the rear valve block to the rhr air strut was not seated on the brass split olive properly (I'll put the photo up)

I want to register my concern at this point. The brass split olive has one purpose, which is to stop the tube blowing out of the connection. There are 2 seals in those connectors. One is an elastomer seal inside the brass body and seals the tube to the body while allowing it to move a little bit, and the other is the external o-ring that seals the connector to whatever it's being screwed into.

This isn't a hydraulic coupling where the olive provides the seal.

So whilst I appreciate the fact the fault has "gone away", I'm yet to be convinced that is/was the cause. I hope time will prove me wrong.

Regardless, I'll bet you know an awful lot more about the vehicle than you did at the start of this "adventure".

[PerthDisco]

I want to register my concern at this point. The brass split olive has one purpose, which is to stop the tube blowing out of the connection. There are 2 seals in those connectors. One is an elastomer seal inside the brass body and seals the tube to the body while allowing it to move a little bit, and the other is the external o-ring that seals the connector to whatever it's being screwed into.

This isn't a hydraulic coupling where the olive provides the seal.

So whilst I appreciate the fact the fault has "gone away", I'm yet to be convinced that is/was the cause. I hope time will prove me wrong.

Regardless, I'll bet you know an awful lot more about the vehicle than you did at the start of this "adventure".

Getting hoses back into that back block during any service procedure has an 11/10 chance of stuffing up.

[Iherbst87]

I want to register my concern at this point. The brass split olive has one purpose, which is to stop the tube blowing out of the connection. There are 2 seals in those connectors. One is an elastomer seal inside the brass body and seals the tube to the body while allowing it to move a little bit, and the other is the external o-ring that seals the connector to whatever it's being screwed into.

This isn't a hydraulic coupling where the olive provides the seal.

So whilst I appreciate the fact the fault has "gone away", I'm yet to be convinced that is/was the cause. I hope time will prove me wrong.

Regardless, I'll bet you know an awful lot more about the vehicle than you did at the start of this "adventure".

Hi BradC. I did check the seals all round and found them to be in good knick, also applied a small amount of red rubber grease to help them slide over the tube. So those 2 seals inside the brass nut were sitting over the old grip marks on the tube causing air to be expelled under pressure (This is my conclusion anyways). So after a few days the car is still running mint with no issues, took it out the back bush and tested it out.