So after getting a new compressor fitted 3 weeks ago and all being ok I now have more issues. I noticed the rear passenger side tyre bouncing around on the 4x4 screen going quite low and high and I got a suspension error normal height only error. Now when I park the car and lock it within an hour both front sides drop to access height rear stays high. I start the car and the compressor kicks in but the car moves up and down constantly until the bong goes off normal height only. I've pulled the eas fuse tonight to see if anything drops (after getting the car to settle at normal height) any thought of what this could be? If the rear height sensor is no good why would the front drop? Could this be a front valve block as the front drops? Could the suspension need re calibrating as when I get in the 4x4 screen shows each tyre at different heights before i turn on the ignition. I known I need a diagnostic tool to read codes which I don't have at present but saving for one. Would a hard reset do anything in this case. Many thanks for any input.
Defo need codes, other wise you will be chasing imaginary faults.
Done any other work recently? distrubed the height sensors or their wiring?
Had a good look around the compressor and its wiring?
Literally could be one of a hundred things.
The IID is the best tool, but way cheaper and pretty good is the icarsoft jobby at about 100 quid.
Done any other work recently? distrubed the height sensors or their wiring?
Had a good look around the compressor and its wiring?
Literally could be one of a hundred things.
The IID is the best tool, but way cheaper and pretty good is the icarsoft jobby at about 100 quid.
No no other work done. Car was fine for 3 weeks pulled the fuse earlier about 2 hours ago just been out and both sides have dropped at the front. Going to have a good look around the compressor and struts tomorrow leaning toward front valve block due to front dropping as it is. Think the bouncing tyre is a separate issue. Can I access the valve block for a visual inspection without removing the tyre as I have limited tools. Really don't want to fork out £50+ for another diagnostic.
I would say you have either a defective rear passenger height sensor or a faulty cable feeding it. I had similar on my L322 with just a slight twitch on the screen which I eventually tracked down to a bodged repair in the loom.
The L322 wakes up every 6 hours and the suspension tries to level to the lowest wheel height, not sure if the disco is the same.
As @lynall said diagnostics should help. I would ignore the valve block for now since you know you have an issue with the rear n/s I'd fix that first.
The L322 wakes up every 6 hours and the suspension tries to level to the lowest wheel height, not sure if the disco is the same.
As @lynall said diagnostics should help. I would ignore the valve block for now since you know you have an issue with the rear n/s I'd fix that first.
Mine could never make it's mind up which corner would drop, one day front, next day rear, sometimes none.
Sounds like you deffo have a dodgy sensor or connection on that wheel. I had the same bouncing when parked and tried 2 new sensors before I found the fault in the loom.
The L322 sensor wears out at the normal height part of the internals so I would assume that the D3 does the same.
This is inside one of my old ones
Sounds like you deffo have a dodgy sensor or connection on that wheel. I had the same bouncing when parked and tried 2 new sensors before I found the fault in the loom.
The L322 sensor wears out at the normal height part of the internals so I would assume that the D3 does the same.
This is inside one of my old ones
So I think I've ruled out the front valve block. I had a check around for leaks to no avail checked the fuse etc and just ensured all was seated correctly. Since then the front hasn't dropped as it did. I did notice that if I had my foot on the brake and indicated right the rear fog light would flash in tandem with the indicator. Changed the bulb which fixed this. Would a bad bulb cause other errors to occur? Definitely getting the rear left height sensor replaced as it moves alot.
Nodge68
Well-Known Member
Yes, bulb faults can throw up all sorts of odd problems.
If the height sensor is physically damaged, then replace it, however to find less obvious issues, you need to run a diagnostic on it, as these are complicated machines.
Wise d3 owners carry spare brake lights bulbs and a spare brake light switch.
I have heard of faulty brake light bulbs doing all sorts of weird things on the D3, I have had several brake bulbs blow, yet never encountered any weird goings on, but you never know which is why I carry bulbs and switch!
Just a thought, and feel free to take the p1ss. If the height sensor is worn at normal height it will cause the erratic display but is it erratic at access or off road height where the sensor is less worn?
I've cycled through from access to off-road when I've been parked and the tyre is bouncing and it doesn't seem to move other than normal height. Also when I park the tyre in question is bouncing and the compressor kicks in to adjust sometimes it stops and starts due to the erratic tyre (my theory)
I'm not familiar with the D3 but I suspect you are right.
Nodge68
Well-Known Member
What do you mean by "bouncing"? The wheel is on the ground, so can't really bounce as such. Do you mean the suspension isn't moving smoothly over it's range?
Can you post a video on YouTube, showing the issue?
I mean the wheel display on the 4x4 info screen. As above the front dropped again but this was after I had parked and the compressor kicked in and the back wheel was moving about(on the 4x4 screen) I don't understand why the front drops if the cause is the height sensor at the rear. To me this only happens if the car struggles when stopped to level and compressor kicks in which then can't adjust to the faulty height sensor runs and then throws up a suspension error to protect the compressor.
Also I dropped to access height the rear left on the info screen bounces I can feel the moving at the rear also noted a red line above the tyre on the 4x4 screen
Also I dropped to access height the rear left on the info screen bounces I can feel the moving at the rear also noted a red line above the tyre on the 4x4 screen
I have had a read of the D3 manual and IMO it's not dissimilar to the L322.
This is how I see it. The height sensor has a 5v supply which supplies a signal to the ECU that only varies by about 1v from access to off road height (my rear n/s ranges from 1.96v @ access to 2.96v @ off road height).
As you can see the ECU is dealing with very small voltage changes so a worn sensor or bad connection can have a major impact.
The manual says "When the vehicle is parked, the air suspension control module 'wakes up' two hours after the ignition was last switched off
and then once every six hours. The vehicle height is checked and if the vehicle is not level within a pre-set tolerance,
small downwards height adjustments may be made automatically".
IMO it could be that as the car tries to level the voltage goes out of tolerence so the ECU throws a hissy fit and gives up half way through.
The OP's description is exactly the same as I posted in the RR section a while ago re mine. If you monitor the voltages with diags they should vary slightly in sync with the 4x4 screen.
My interpretation of the symtpoms is the left rear twitching on the screen with the orange line and wheel moving up and down slightly
Then when it goes into fault mode the wheel drops (on the screen) and displays a red line.
(Picture is from my issue with the front n/s)
As I say this is how I see it, happy to be corrected if I'm talking bollox. At which point I can correct/delete so future readers of this post don't follow a load of rubbish.
This is how I see it. The height sensor has a 5v supply which supplies a signal to the ECU that only varies by about 1v from access to off road height (my rear n/s ranges from 1.96v @ access to 2.96v @ off road height).
As you can see the ECU is dealing with very small voltage changes so a worn sensor or bad connection can have a major impact.
The manual says "When the vehicle is parked, the air suspension control module 'wakes up' two hours after the ignition was last switched off
and then once every six hours. The vehicle height is checked and if the vehicle is not level within a pre-set tolerance,
small downwards height adjustments may be made automatically".
IMO it could be that as the car tries to level the voltage goes out of tolerence so the ECU throws a hissy fit and gives up half way through.
The OP's description is exactly the same as I posted in the RR section a while ago re mine. If you monitor the voltages with diags they should vary slightly in sync with the 4x4 screen.
My interpretation of the symtpoms is the left rear twitching on the screen with the orange line and wheel moving up and down slightly
Then when it goes into fault mode the wheel drops (on the screen) and displays a red line.
(Picture is from my issue with the front n/s)
As I say this is how I see it, happy to be corrected if I'm talking bollox. At which point I can correct/delete so future readers of this post don't follow a load of rubbish.
Thanks for that.
Today picking my daughter up from school I parked the car rear wheel all over the place on 4x4 screen. Came back 20 mins later front end down to access height rear ok. Could the car register a fault with the height sensor and when I switch off it knows it wasn't level try and self level sees an issue drops front to access as that would be level but when it comes to the back the signal from the height sensor is bad so it doesnt do anything?
Just trying to get my head around how it works.
Today picking my daughter up from school I parked the car rear wheel all over the place on 4x4 screen. Came back 20 mins later front end down to access height rear ok. Could the car register a fault with the height sensor and when I switch off it knows it wasn't level try and self level sees an issue drops front to access as that would be level but when it comes to the back the signal from the height sensor is bad so it doesnt do anything?
Just trying to get my head around how it works.
IMO as soon as it sees an issue it should just throw up a fault and stick at whatever height it's at. My fault was caused by some plank twisting twisting the two ends of a broken wire together rather than soldering it so as the wires started to go green the voltage became more and more unstable and confused the ECU, once the ends were soldered properly the fault went away.
As said by others you need to get it on diags and confirm if it is just a faulty sensor in which case it will need calibrating anyway when the new one is fitted.
Even if you just throw a sensor on it will still need calibrating so it's still back to diags.
I also think you are chasing a red herring with the front dropping, as I say mine did lots of silly things but since I fixed the loom (touch wood) it been fine for about 2 months, which is a record in the 2 1/2 years I've owned it.
As said by others you need to get it on diags and confirm if it is just a faulty sensor in which case it will need calibrating anyway when the new one is fitted.
Even if you just throw a sensor on it will still need calibrating so it's still back to diags.
I also think you are chasing a red herring with the front dropping, as I say mine did lots of silly things but since I fixed the loom (touch wood) it been fine for about 2 months, which is a record in the 2 1/2 years I've owned it.
So another morning of head scratching I decided to have another inspection of the lines and struts. I put the car in offroad switched off the ignition and had a good listen. What I discovered is every minute of 2 I could hear a short spurt of air being vented not sure where it is coming from but it's like a very short burst for less than a second of air then it stops then another for about 4/5 spurts. What would be sending a signal for this to happen it's 100% causing the vehicle to lower like mentioned above when turning back on the ignition on the 4x4 info screen all tyres seem to be at different heights. Is this a re calibration issue as if once switched off the car keeps venting air to get the pre set calibration definitely a head scratcher.
