R

RRkev

Active Member
hi guys any help appreciated on this one, currently my 2003 vogue is sitting low on one rear corner, have checked for errors using hawkeye but nothing is showing as an error. the left rear is sitting 20mm lower than the right rear, i've measured the heights this morning and found the right rear is spot on where it should be 750mm and the left rear is 730mm, there is also a difference the same on the front with front left where it should be and front right approx 20mm higher (although this could be because rear is pulling it up). the height difference is present through all suspension height modes.

so far i've had suspension bushes checked and all seem to be ok, the suspension compressor isn't working anymore than it normally would and the car does not sag lower when not in use indicating no leak. this all seemed to start back last year when i had the engine ecu go faulty and was sending errors all over the ibus (causing loads of errors, suspension inactive, hdc,abs, auto trans failsafe etc). this could be the cause or just coincidence.

i've checked ride height sensor reading with hawkeye and they all seem to be around the same even with the height differences
i'm wondering could i just need to get the suspension recalibrated or something more involved causing the problems?
 
Recalibration would be the first step....

The sensors are not precision devices, so they won't read exactly the same....some will some won't

Also check the condition of the air springs, if original, they'll be tired now!
 
Front 2 have been replaced, 1 by Me one by previous owner not 100% sure on rears, one front height sensor has been replaced too, which is front left which is at correct height
 
Also the Engine ECU shouldn't cause issues on the I data bus....it communicates over the CANbus.

CAN bus is for Powertrain, Steering, Suspension and Brake Systems
I Bus is for the Infotainment Systems
K bus is Body Systems
M bus is the Heater and Blower controls
P bus is the BCU to 'peripheral' ECUs


Now, that being said, when a HID lamp blew in mine, it caused diagnostics bus failures, but that is because they all communicate via the Instrument Pack.
 
canbus was what i meant, when engine ecu went faulty all the canbus linked ecu's displayed faults, it could be coincidence that the suspension has sagged on the one corner at the same time but i think calibration is my starting point, now do i pay a garage or just buy an allcoms lol,it's a shame i bought a hawkeye really lol
 
Put your location down, you may be local to someone who can oblige!

All Comms is a great piece of kit!
 
+1 to allcomms recalibration, this may be a stupid answer.. but its not self leveling is it as mine sits like that on my drive as my drive isn't level so the car adjusts the susepnsion heights to make the body level
 
No good point but no wherever I park the car it is definitely sagging in bottom left corner, it's only 20mm but looks a lot worse when looking at the actual car
 
20mm isn't a massive difference

Check your suspension height sensors

Usually that age of car all of the height sensors need replacing as they become perished and faulty
 
holidaychicken said:
+1 to allcomms recalibration, this may be a stupid answer.. but its not self leveling is it as mine sits like that on my drive as my drive isn't level so the car adjusts the susepnsion heights to make the body level
Click to expand...
Not entirely accurate.....

The EAS will level itself to make the sensors read the values as stored during calibration.

Whilst generally if the vehicle is on a slope, gravity will try and pull one side or corner down further than the other, so the system will try to counter this by pumping up that side to realign the sensor values but it cannot make the vehicle body sit level like a bubble in a spirit level! It merely tries to maintain a set ride height, not vehicle level as such!
 
I think I'll plug my Hawkeye in tomorrow and check height sensor readings etc and see if that sheds anymore light on the problem, but def going to head down the calibration route first I think
 
so i've been out and had a look this morning, i've checked rear air springs and they don't look too bad no signs of any bad perishing on them so i think these may have been replaced. i've used hawkeye to check all the actuators on the system (air valves etc) and these have all checked out ok and are sending/receiving signals as they should.

run the car from full height down to access height a few times whilst checking live data on the height sensors and these seem to run smoothly with no drop outs or blank areas in the readings.

i've also checked the heights in my ecu and it should be standard height 0mm, motorway -20mm, access height -40mm. with 10mm difference front to rear
my current readings at standard height are.
Fl -13
Fr 14mm
Rl 13mm
Rr -10mm
these height differences remain about the same at all heights with 1mm deviation.

height sensor voltages at full height seem to tally too taking differences into consideration.
although i think the front right reading maybe a little low so possible dodgy sensor?
FL 2.56v
FR 1.95v
RL 2.69v
RR 2.29v

so it's now fingers crossed it just needs calibrating or possibly a height sensor too
 
Saint.V8 said:
Not entirely accurate.....

The EAS will level itself to make the sensors read the values as stored during calibration.

Whilst generally if the vehicle is on a slope, gravity will try and pull one side or corner down further than the other, so the system will try to counter this by pumping up that side to realign the sensor values but it cannot make the vehicle body sit level like a bubble in a spirit level! It merely tries to maintain a set ride height, not vehicle level as such!
Click to expand...

hmm that's worrying then, as when i look out onto my drive, the Range seems to sit level but i know the drive doesn't, maybe i have just been kidding myself as i thought that's what was happening, I'll have a look next weekend..could be my eyes
 
Saint.V8 said:
Not entirely accurate.....

The EAS will level itself to make the sensors read the values as stored during calibration.

Whilst generally if the vehicle is on a slope, gravity will try and pull one side or corner down further than the other, so the system will try to counter this by pumping up that side to realign the sensor values but it cannot make the vehicle body sit level like a bubble in a spirit level! It merely tries to maintain a set ride height, not vehicle level as such!
Click to expand...
So what does it do if one wheel is in a pothole?
 
Datatek said:
So what does it do if one wheel is in a pothole?
Click to expand...
Tries to relevel the car so the sensors ride the stored values for the current ride height as best as possible.

The system does understand that in some circumstances, when it relevels itself to maintain the sensor readigs for a given ride height, that it may not fully achieve this...i.e. lower FL corner and RR will increase so it tries to maintain a median reading across the sensors!

Remember the sensors read position of the subframe to suspension arm, all it tries to do is maintain the angle/distance from subframe to suspension arm, it cares not if the car is upside down in a ditch!
 
it explains when getting the tracking adjusted if i don't put it into tracking mode with hawkeye if they have to pull on the nuts a little harder than norm and it cause suspension to move the car starts adjusting itself
 
Saint.V8 said:
Tries to relevel the car so the sensors ride the stored values for the current ride height as best as possible.

The system does understand that in some circumstances, when it relevels itself to maintain the sensor readigs for a given ride height, that it may not fully achieve this...i.e. lower FL corner and RR will increase so it tries to maintain a median reading across the sensors!

Remember the sensors read position of the subframe to suspension arm, all it tries to do is maintain the angle/distance from subframe to suspension arm, it cares not if the car is upside down in a ditch!
Click to expand...
The stored values are only target values, there is some fancy maths involved to allow for uneven surfaces, the car can be roughly level with one wheel way off the target values.
 
Datatek said:
The stored values are only target values, there is some fancy maths involved to allow for uneven surfaces, the car can be roughly level with one wheel way off the target values.
Click to expand...

True, as i said, the system knows that achieving the exact settings is impossible, so allowances are made to find a median vehicle level....

I.e. 3 wheels are almost on the set points but one isn't so the system reckons that one wheel is in a hole and ignores the 4th wheel, but if the 4th reading is so implausible that the system knows that even in the worst case the physical suspension geometry couldn't even achieve such readings, it issues an Articulation Plausibility fault...as it thinks things have gone awry.
 
well a little update on this had the recalibration done today and all is kind of well, rear end now sitting level, left was 11mm down and right was 9mm up, which caused the front to do all sorts of adjustments so front left to right is now within 2mm unfortunately though my upper and lower front suspension arms are goosed they drove the car in and broke hard and showed me the wheel moving so thats my next job had a pretty decent quote for 4 arms tracking & labour (only quoted 45 mins to do arms) the arms were done 22,000 miles ago the day before i bought the car, my guess is the owner used cheap pattern parts as he was selling it, i've been quoted on delphi replacement parts this time
 
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