Suspension Fault

[devo]

Hi all,

Have a 2009 Discovery.
Suspension light came on and was to busy at the time to sort it.
I drove for a few days and presume from reading here that it burns out the pump.
Noticed one day that the left front suspension was down more than right.
Decided to replace the front air springs and buy a chinese replica of the original pump to try before I outlay for the original.
Fitted air springs and pump but the pump wont run.
Nanocom fault codes are

U0164, UV0421, U0421.
Can anyone give me an idea where to start with rectifying this issue.
I try to do all my own work to keep me in-touch with my 185,000km disco but this has me stumped asI don't understand the suspension yet

Thanks for reading
Devo

[Eric SDV6SE]

These all appear to be comm codes, most likely due to the replica compressor you've fitted not talking to the BCM.

The Hitachi (and I think the AMK, but not sure, these were fitted to later models, so I'm pretty sure you have a Hitachi unit) compressors are fully rebuildable, you can get kits off Ebay that includes everything you need. most likely you've got desiccant dust in the lines or a leak somewhere.

Check that the airlines are fully pushed home into the top of the air struts and at the compressor outlets. do the soapy water check at each valve block.

Good luck

[loanrangie]

I doubt you need the new struts although they may be tired, more likely to be the front valve block and as Eric said the cheap pump.
Better off rebuilding your original compressor and putting it back in.

[scarry]

The valve block can leak back internally which is not an uncommon issue.

[devo]

Thanks for the positive responses.

Yes it is the Hitachi pump.
Yes. The message with the code was a communication problem. But where to start?

At the time of the original problem I didn't have a code reader so I was guessing and
I bought the Hitachi replica as i'm not sure if the original pump works still. I have read that if the fault light on the dash is ignored then the compressor motor burns out.
I am unable to check for air leaks presently as the pump replica does not run and therefore no air.
Is it possible to to check the old pump motor on the bench and if so what wires power the motor.
As for the valve body. Can the front valve body be overhauled or is it better to just buy a new one.

I feel I need to establish if the old pump motor still works.
As "suspension fault" was showing on the dash display and the old pump was not working I presume that the motor is burned out.

Any help appreciated
Graeme

[loanrangie]

If the light was still orange there's a good chance the compressor still works, when it gets to red and ignored it will run longer then burn out.
Valve block can be rebuilt with a seal kit but instead of stuffing around just buy a new one unless you have time to wait for parts.

[PerthDisco]

Check first the large main fusible link fuse in the engine bay fuse box closest to the front of the car. It’s a rectangle yellow colour 60amp or thereabouts. They blow with age and you can see looking above through the clear top. Then no juice to the relay or compressor.

You can bridge the big terminals (female side) of the EAS relay and force the compressor to run as another test.

They are big cables that run to the compressor main power feed.

[shamirj]

Does the valve block throw up a error message, I am guessing mine has a faulty valve block which can be bought for $100 approx from ebay cheapest or $400 genuine (referring to the fronts) only, but I do not get any faults when checked on the icarsoft code reader. My rears sag as well, so guessing I will need to replace both front and rear. cheers

[Plane Fixer]

I recently bought a genuine made in Japan Hitachi compressor from Island 4x4 delivered for just under $AU800 and fitted it last week. Solved my slow to raise warning. I did not consider the cheap knockoffs at that price.

[Bulletman]

Undo the power plug going to the compressor and run pos and neg straight from a 12v battery to the compressor , the compressor should run. You can then rule that out. check the relay, fusible link and the fuses in the engine bay, they are labelled under the cover .

The car will self level , so you may only have 1 leak but the car performs self level every 6 hours or so and this will cause all the airbags to deflate.

If you can get the car to pump up , pull the 20a fuse in the engine bay, this will stop the self levelling and you will see if the front or rear drops. A leaking valve block will see the front drop on both sides , a leaking airbag will drop only on that side.

Valve block rebuild is very easy , you tube is your friend, you just need to order the oring kit which you get from the uk , but after doing it myself recently i would think CBC or similar would have them on the shelf , you just need to get them out first to get the correct size.

I have also had a faulty brake light switch throw up suspension fault but the car didnt lower it just stayed at normal height and took out the ability to raise or lower the car.

Bulletman

[stuarth44]

The valve block can leak back internally which is not an uncommon issue.
saw you have a 56 S1, mine was 57, was as new when I bought in 68,they never had floating axles and the axles never broke, the came the S11 and 11a,valves abt 1500omiles clutches main boxes all gave poor mileage, I worked at LR Main dealer in Auckland ass an apprentice, i became very quick at gearbox overhauls

[devo]

Problem solved.

Went back and started again.
Filled the original air springs with air from my shed compressor. One of the bags has a definite leak. Suspect that was the one from the left front but not certain.
With the old pump on the bench I connected the motor to a battery and the old pump works.
Without the airlines connected I connected the pump to the disco wiring again and the pump didn't run.
Went back and checked the 20A fuse and that was ok. The 60A fusible link looks ok through the clear cap but was stuffed. I took the cap off and closely inspected the fuse but looked ok. checked with ohm meter and it showed an open circuit. Poked the fuse lightly with a probe and the fuse was no longer soldered at one end.

The good out of this is that with the suggestions from members I have learned a little about the suspension while broken down at home. I have just ordered an overhaul kit for my original pump and will return it to service and now will have a the new pump as a spare. have ordered valve block kits as well as there is a lot of dust in the pump canister. Time to change the Desiccant.

Thanks everyone for your help
very much appreciated.

[PerthDisco]

Problem solved.

Went back and started again.
Filled the original air springs with air from my shed compressor. One of the bags has a definite leak. Suspect that was the one from the left front but not certain.
With the old pump on the bench I connected the motor to a battery and the old pump works.
Without the airlines connected I connected the pump to the disco wiring again and the pump didn't run.
Went back and checked the 20A fuse and that was ok. The 60A fusible link looks ok through the clear cap but was stuffed. I took the cap off and closely inspected the fuse but looked ok. checked with ohm meter and it showed an open circuit. Poked the fuse lightly with a probe and the fuse was no longer soldered at one end.

The good out of this is that with the suggestions from members I have learned a little about the suspension while broken down at home. I have just ordered an overhaul kit for my original pump and will return it to service and now will have a the new pump as a spare. have ordered valve block kits as well as there is a lot of dust in the pump canister. Time to change the Desiccant.

Thanks everyone for your help
very much appreciated.

Good one. Change EAS relay at same time as fuse.

[Bulletman]

Problem solved.

Went back and started again.
Filled the original air springs with air from my shed compressor. One of the bags has a definite leak. Suspect that was the one from the left front but not certain.
With the old pump on the bench I connected the motor to a battery and the old pump works.
Without the airlines connected I connected the pump to the disco wiring again and the pump didn't run.
Went back and checked the 20A fuse and that was ok. The 60A fusible link looks ok through the clear cap but was stuffed. I took the cap off and closely inspected the fuse but looked ok. checked with ohm meter and it showed an open circuit. Poked the fuse lightly with a probe and the fuse was no longer soldered at one end.

The good out of this is that with the suggestions from members I have learned a little about the suspension while broken down at home. I have just ordered an overhaul kit for my original pump and will return it to service and now will have a the new pump as a spare. have ordered valve block kits as well as there is a lot of dust in the pump canister. Time to change the Desiccant.

Thanks everyone for your help
very much appreciated.

I have had a very slow leaking front airbag for several months and i recently had the car throw a fault something along the lines of not exhausting air pressure. I did notice that when i stopped the car it didnt fart no more and wouldnt do its levelling thing. 6 months before that i had replaced my dissicant as the cap on my pump housing blew off

Admittingly I live in the tropics and we have had an above average wet season with several months of humidity in the 90% most days but this is a pic from my recent issue
169238 the rusty 1 was on the bottom closest to the pump.....

I can only assume moisture enters the system when you have a leak in the air system and the filters in the dissicant housing take the brunt of it. I did also notice a very fine powder in my front valve block when i re - oring it. I emptied the dissicant into a sieve and filtered out the powder and then just baked the beads on a tray in the oven and topped up with some spares that i have.

cheers Bulletman

[Parso]

Just changed out my desiccant as the car hadn't been farthing but my amber light continues. No drop overnight, front and back valve blocks replaced in the last year. Any other suggestions?

[Bulletman]

Just changed out my desiccant as the car hadn't been farthing but my amber light continues. No drop overnight, front and back valve blocks replaced in the last year. Any other suggestions?

If you have a D3 check your brake light switch. mine was working but only intermittently so took a few goes to see that the brake lights didnt always come on when i pressed the peddle. The is some sort of canbus feed that goes thru the brakelight switch that faults the suspension. You can get them cheap at a Ford dealer as the territory and i think some model falcon use the same switch.

Im not sure if the D4 is the same or if that was rectified.

Bulletman

[Parso]

If you have a D3 check your brake light switch. mine was working but only intermittently so took a few goes to see that the brake lights didnt always come on when i pressed the peddle. The is some sort of canbus feed that goes thru the brakelight switch that faults the suspension. You can get them cheap at a Ford dealer as the territory and i think some model falcon use the same switch.

Im not sure if the D4 is the same or if that was rectified.

BulletmanI have a spare I'll throw it in and see

[Parso]

If you have a D3 check your brake light switch. mine was working but only intermittently so took a few goes to see that the brake lights didnt always come on when i pressed the peddle. The is some sort of canbus feed that goes thru the brakelight switch that faults the suspension. You can get them cheap at a Ford dealer as the territory and i think some model falcon use the same switch.

Im not sure if the D4 is the same or if that was rectified.

Bulletman

Put my spare in but sadly the fault continues to come on after about 30 seconds

[scarry]

Put my spare in but sadly the fault continues to come on after about 30 seconds

You need to read the code, that will reveal what is going on.

[matti4556]

Put my spare in but sadly the fault continues to come on after about 30 seconds

What condition were the felt pads in when you changed out the dessicant? Mine were blocked solid - clean felt pads and bingo = all good - but yes, sage advice is to get the codes read. - Matti

[Parso]

You need to read the code, that will reveal what is going on.

Yeah probably time to cave and buy a Gap tool... then a new compressor [bawl]

[Azza_LR3]

Hi All,
Ive encountered an unusual problem. I recently had my car at an auto elec to wire in a compressor for offload driving (tire inflation), when I got car back, dash warnings indicated suspension fault. I had initially though they had bumped something under the dash.
The and suspension dropped. I restarted the car and this went away, temporarily. SO I managed to get home, only to plug in scanner to read for faults.
Fault indicated that the Front Left ride height sensor was not responding. SO I plugged in my X Lifter, this confirmed the front left corner wasn’t reading a ride height sensor. (See photo)
Naturally I replaced this sensor with a tested 2nd hand one. and Suspension continues to fault. SO assuming id been sold a dodgy sensor, i replaced it with a new one. Still same issue.
Suspension fault, Initially the HDC light in dash was red, and the illumination under the console switches was non existent. Now, im back to Yellow HDC dash light, and the console lights, until the ECU realises their still is an issue, and they turn off. The car is still sitting down and won’t raise.

Has anyone encountered this issue before? if so, how do i fix this?

[josh.huber]

Grab a wiring diagram.. Check the sensor for a power supply and earth return first. Check for blown fuses. Maybe the auto elec made a whoppsy on the install. Or hasn't plugged something back in

[Eric SDV6SE]

I reckon they've grabbed the nearest live wire and spliced into it, now the EAS thinks one of the sensors is faulty. Undo the wiring that the leccy has done and see if the problem persists.

[Azza_LR3]

Hi All,
Ive encountered an unusual problem. I recently had my car at an auto elec to wire in a compressor for offload driving (tire inflation), when I got car back, dash warnings indicated suspension fault. I had initially though they had bumped something under the dash.
The and suspension dropped. I restarted the car and this went away, temporarily. SO I managed to get home, only to plug in scanner to read for faults.
Fault indicated that the Front Left ride height sensor was not responding. SO I plugged in my X Lifter, this confirmed the front left corner wasn’t reading a ride height sensor. (See photo)
Naturally I replaced this sensor with a tested 2nd hand one. and Suspension continues to fault. SO assuming id been sold a dodgy sensor, i replaced it with a new one. Still same issue.
Suspension fault, Initially the HDC light in dash was red, and the illumination under the console switches was non existent. Now, im back to Yellow HDC dash light, and the console lights, until the ECU realises their still is an issue, and they turn off. The car is still sitting down and won’t raise.

Has anyone encountered this issue before? if so, how do i fix this?


So after some fault finding ... I found this issue.. Bloody 2nd hand ride height sensor was dodgy. I replaced this with a new one, reset codes, and boom.... car is back to life.... did momentarily flash a code of ride height module, but cleared that, and no dramas. Went for a drive and checked codes again.... all clear so far...
Thanks for the help guys..