rear suspension dropped suddenly

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J

jay572

New Member
Posts
100
Location
liss hampshire
hi all wa smy disco 2 2000 model driving home last night and the rear suspension dropped suddenly to its arse!! the warning light came on but if i push the hight raise button nothing happens, the air bags have never dropped over night or days have checked the fuse and the relay all ok, when i press the raise button i cant feel the compressor working?? if the compressor fails does it dump all the air in the suspension?? i;ve run out of ideas?? also could i drive it about 10 miles on the bump stops slowly?? shouldn't the compressor try to inflate the suspension even if it is leaking?? please help!!!
 
A faulty compressor must not release air unless its body cracked. it should inflate leaky bags untill it'll burnout. Leaks doesnt give warnings on dash. It seems a ride height sensor, exhaust valve issue to me or quite uncommon but possible an ECU failure. Try to jack the back up and turn ignition on(all doors and bonnet closed) if its ride height related u might fool the sensors and get the compressor feeded. U can try to go slowly on bump stops if u have normal tyres and u dont feel big rubbing noise.
 
thanks for the reply will jack it up on the body tomorrow, i don't think its a leak but am not sure why the compressor is not working or why it dropped. i have 18in general grabbers on!! two weeks old donna if i should risk it theres about 5 mm clearance hmmmm... what does the exhaust valve do?? and what parts are there to go wrong on it?? many thanks
 
jay572 said:
thanks for the reply will jack it up on the body tomorrow, i don't think its a leak but am not sure why the compressor is not working or why it dropped. i have 18in general grabbers on!! two weeks old donna if i should risk it theres about 5 mm clearance hmmmm... what does the exhaust valve do?? and what parts are there to go wrong on it?? many thanks
Click to expand...

it's releasing the air commanded by the ECU.......it's a solenoid valve, it could be blocked open..... the best thing to do is to read the fault code and then u'll see the failure....cos if the warning lamp is on the fault is logged and described.....find someone with dedicated scanner
 
ok thanks have lost that thread was it pin 83? fuse no? and relay no? sorry..also would i be able to drive it home like this if they inflate?? and how would i enable the sly by just putting the fuse and relay back in?
 
jay572 said:
ok thanks have lost that thread was it pin 83? fuse no? and relay no? sorry..also would i be able to drive it home like this if they inflate?? and how would i enable the sly by just putting the fuse and relay back in?
Click to expand...

Disregard that message, there are more bypasses to do, quite complicated
 
The "disabling SLS and inflating" mode is the following...u have to unplug all the connectors from the compressor housing then use wires to connect together all pins 2 of male connectors C0780 - C0782 - C0783 and give earth...then pins 1 of the same connectors together and +12v...cut this feed when height is normal(u can leave the earth)...leave connectors disconnected and if there are no leaks in the system it'll stay levelled. U dont have to disturb any fuses or relays this way.

connectsls.png
 
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i will give it ago if it stays up it will get me home also guess it will tell me it might be the solenoid valve guess is located on the compressor or even the ecu. thats dumping all the air for some reason. it will rule out any leaks and the compressor. thanks
 
The ideea is to feed the compressor and both(RH and LH) air valves at the same time and then the air will go into the air springs...when u'll cut the feed the air must stay there if no leaks are present. Here's another scheme to make it clearer

compressor.png
 
Have you tried disconnecting the air lines at the pump manifold and injecting compressed air into the bags using a simple adaptor, watch for rise listen for leakage at rear susp ? Air bag failure is reasonably common on Rangies maybe Disco also?
 
thanks for your help sierrafery, i did what you suggested and unplugged the compressor and hot wired it to a battery. The air suspension raised on the compressor i disconnected the battery and the rear stayed up, so then i reconnected the wiring from the landy to the compressor everything ok, suspension raised and lowered i took it for a drive all ok, turned it of then on again all good. went inside for a **** come out and its on its arse again!!! so i turned it on shut the door and it started rising again got half way then the compressor shut off it dropped again and the warning light came on and thats it!!! I noticed earlier that with nothing on the left hand solenoid was making a ticking noise, was wondering if it could be getting a feed from the ecu which keeps it open or wether it might be stuck open if this is the case would the suspension drop or would it also need the exhaust solenoid to open??? thought i might remove the electrical connector to the left hand solenoid test it back to the ecu to see if its getting a stray voltage or not............ if theres not do you think it might be the solenoid?????
 
Do again the "non SLS" thing with everything disconnected and leave it so for longer period(all day and night) if it stays levelled its certain that the exhaust valve is getting command from mthe ECU......this could be due to a ride height sensor, a door or bonnet switch or even ECU malfunction. If it's so leave it disconnected cos it'll stay up for days(unless u have a leak somewhere too. If it'll drop with electrics disconnected then it's a leak or the exhaust valve...... though a simple leak doesnt generate warnings on dash. The ultimate answer will be given by a dedicated scanner.
 
went out this morning quickly!!!! pumped it up and disconnected everything going to leave it now as you said see if it drops at all, got a guy coming out next week with a diagnostic tester as the warning light on the dash is still on will let you know the outcome... many thanks for your help
 
I hope the man who'll test it knows how SLS works coz when the tester will be plugged in u might have more errors now than the "original" one. Some errors will be logged due to the fact that u've disconnected the plugs and the ECU recognised it as an error. Disregard the errors related to compressor or RH/LH air supply valves....if with the plugs disconnected the car will stay on level u can disregard the exhaust valve too....it means that everything within the compressor housing is faultless. If there will be faults on the ride height sensors or anything else then that's the real fault. Anyway to make sure u can ask the guy to erase all faults, take a ride with everything reconnected, then go an take another ****:D untill the car drops and the warning comes back.....in this case u'll have just one error logged(i hope).... the real one.
In the other case.... if it'll drop with all the plugs disconnected then it's a leak or blocked exhaust valve and that one u'll have to locate it with loads of soapy water and much of patience. GOOD LUCK
 
I think there may be a suspension thief about. You're not the first person he/she's targeted...
 
update so far.... have pumped up the suspension about 11 hours ago disconnected everything, and it hasn't moved a bean (sad i know but i measured it!!) so from that with your help seirrafery i can rule out air bag leaks, pipe leaks, compressor, left hand and right hand solenoid as well as the exhaust solenoid letting by.. i think my next option is to some how check the ride height sensors i don't know how suppose i check connections, check for damage and check they move freely????? if thats ok my only other options are a loose connection on the wiring or the ecu :mad: will check the basics tomorrow then wait for the diagnostics and as you say rule out the faults showing the compressor and solenoids
 
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