I’ve been through the entire forum with a fine tooth comb but haven’t come up with a solution to my problem, I nearly did when a guy with same problem was going to keep us all “informed” as to the solution then after 10 mins of reading and 5 pages later, never bothered to post how he fixed it. So here goes. I have a 2004 d2 the system has no leaks and holds air very well, however whilst driving it just dropped it’s pants down to the bump stops and I had to crawl home at 2mph, the button did noting and just flashed and bonged at me. I reversed onto my parking space, ploughing it as I went because the tow hitch was less than an inch from the floor. After a head scratch I started it up through the window (doors shut) it raised up to height and operates as expected when pressing the off road button, up and down to normal height. It’s holds air for and has for the last 3 days, there’s no leaks, does this sound like the tide height sensors getting confused or does anyone think it’s something else ??
 
id change both sensors they arent that dear and usual culprit, i did have a similar truck in which would that did similar fitting new air bags cured it but i was never really sure quite why
 
It's hard to tell when it's about a symptom which happenned only once and never since, it could have been an ECU missbehaviour due to a voltage drop or momentary missing earth or something... can be bad contact in one of the sensor's plugs cos those are common to fail...the warning lamp protocol is not the best for the SLS system so make somehow to plug in a dedicated tester and see if there is some fault code stored maybe that will give some ideea
 
Thanks for the replies, I failed to mention that it’s dropped to the bump stops a couple of times and was unresponsive to any call for air via the button, the rear anti roll bar buses have recently been done, although the sensors are in place still it makes me wonder if they got over extended or disturbed too much . Can’t be just coincidence can it ? I guess anything is possible with a disco
 
Not the same car but had a similar problem with P38, Air suspension would just randomly drop, no air leaks, and the compressor was fine, I bought the lead and software and it would reset correctly straight away. I measured all the sides and everything was fine, but it still kept randomly dropping. The sensors all "seemed " ok.
When I finally gave in and decided to try and replace them I found one of the back ones was split, but in such a way that when you looked at it in place it looked fine and was resetting right, but if i hit a certain kind of bump on the road it would put me straight into limp home suspension mode. Swapped the sensor and it cured it straight away.
 
Don't forget to disconnect the battery before you unplug the sensors and verify with attention the connectors to not have corrosion or loosened cavities, that's why THIS KIT (read the description) is well sold and it can be the root of your problem too especially if the new sensors will not fix things
 
I had the opposite where my ride height went up to maximum after pulling off my drive, that turned out to be one of the sensors. It was still connected but the arm was just spinning round the centre spindle. I think it had gone to max as i pulled off the drive where there is a dip and although the arm went back the centre spindle didn't. You could have the same problem in opposite format.
 
The “usual” reasons for errors in the air suspension, and I stress these are the reasons most often noted are when the suspension drops change the bags or if the suspension over inflates change the ride height sensors.

Obviously that’s a bit of an over-simplification, but my advice would be to change the bags first off before digging any deeper into the operation of the self-levelling suspension system. The bags can play all sorts of tricks, so before you tear your hair out, change them and rule them out.

Ride height sensors are fairly cheap too and pretty easy to change. Remember to disconnect the battery first to be on the safe side.
 

Similar threads