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Air Suspension & the Alps :-(


beng
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While taking my RR on a little european trip to the Alps (pics to follow) she decided that a high mountain pass would be an oppertune moment to fail the EAS... but in normal mode. Happily going to unplug the delay relay she beat me too it and dropped to the bump stops. Followed a little bumpy ride to the hotel. With the help of geoff and the internet I got her back up and we had a comfortable ride home.

The question is now what to do. I have tested the compressor and that is fine. My plan is now to test the resistance across each of the height sensors assuming that one of these has failed / gone out of range.

Is this a good plan? Does anyone know what sort of values i might expect? Is there any alternative to taking it to the dealer to have the EAS reprogrammed?

Many Thanks, Ben

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the sensor outputs are 0 to 5V outputs and should be a smooth change through the range of motion. An article here talks about it:

http://rangerovers.net/forum/viewtopic.php?t=14631

In terms of what to do now, what did you bodge to get yourself up and back home? disengage the EAS and manually inflate the air bags? Did the airbags hold their air? If so, then it looks like the physical system is OK but the electrical side aint . . . which your aiming at now anyway.

If you do have replace a sensor unit, then it is likely that you would need the system re-programmed so that the sensor heights are matched to the correct physical heights.

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the sensor outputs are 0 to 5V outputs and should be a smooth change through the range of motion. An article here talks about it:

http://rangerovers.net/forum/viewtopic.php?t=14631

In terms of what to do now, what did you bodge to get yourself up and back home? disengage the EAS and manually inflate the air bags? Did the airbags hold their air? If so, then it looks like the physical system is OK but the electrical side aint . . . which your aiming at now anyway.

If you do have replace a sensor unit, then it is likely that you would need the system re-programmed so that the sensor heights are matched to the correct physical heights.

Hi,

I connected pins 1 & 8 for about 7 mins, then restarted the truck - which majestically rose to normal height. Unplugged the ecu again and returned. After about a day the LHS stayed fully inflated, RHS developed a lean... have since tried same procedure to no avail.

Ben

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by the sounds of the lean, then that would generally make me think there is a leak of some form. In theory, both sides should have been level.

How old are the air suspension bags . . . or probably more to the point, how old is the car?. I personally think of the airbags the same way i would do tyres ( similar material and hold the same weight on each corner). If the springs are older than 4 to 5 yrs, then i would thinking about replacing them all. ( I wouldn't run about on old tyres . . .so why run about on old airbags )

If i were going down that route, then i would also consider replacing the air hoses on the car too. Both the hoses and the airbags are fairly easy operations. Air hose is fairly cheap ( mine was about £15 for 30metres of the stuff ) and the airbags i got from Paddocks as they are the cheapest and are actually the same as the original Dunlop items.

After the airbags, the next main area of leakage is often at the big valve block unit under the bonnet beside the compressor. The little rubber o-ring seals can perish here and leak too. There are kits and instructions a plenty ( rangerovers.net ) on how to repair these, so another area worth looking at too. I'm not sure how much the valve kits cost.

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Having been informed by the local LR dealer that before I change the pot (assuming that one of the pots has failed) they have to back up the ECU to their system (£100+VAT min) and upon completion they will need 1-2 hours to restore the data (200+VAT).

I am fairly convinced that this is not entirely accurate. Can anyone confirm the inaccuracy of their statement? Can anyone recommend a good testbook equiped garage in the Sheffield / Yorkshire area?

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Any thoughts as to what to check on my one? When i finally get the gearbox sorted........with the engine running i get the warning light on all the time (probably needs re-setting).

I tried geoffs method of shorting the pins out, but when I connected pins 1 and 8 together the compressor wouldnt run. I checked and I do have power at pin 1, and I also checked the maxi fuse under the drivers seat which is not blown and I do also have power to it.

My guess was angling towards knackered compressor. However it worked before the gearbox broke and it got parked up for 6 months. Is the compressor likely to have just got stuck? Can they be taken apart and cleaned or summat?

Next thing I was goingto check was that there was actually power to the compressor directly but that involves jacking the truck up and its raining.........

Just thinking ahead really - theres no gearbox in it at the moment anyway, but once thats sorted the suspension is the next job!

Cheers

Jon

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Your stealer is ripping you off big time with those prices imho - to the point it would pay for your own Rovacom Lite at those prices.

In terms of backing up the ECU, that not entirely necessary imho either. The ECU shouldn't need backed up when you change a sensor.

To change a sensor, i'd go through the following:

Park it up on a flat surface and then for each of the height settings, measure the top of the wheel to top of the arch heights ( after you've let it settle on a steady height ) You should then have a table of all the values for all the corners.

Then raise it up to off road height

Switch off

disconnect battery

remove sensor

fit new sensor

connect battery

start it up up.

At this point, the car should not notice that its a new sensor, just that compared to the previous one, the readings are slightly different for each height setting, and it'll adjust the height till it gets the reading its looking for. ( Reality is that its likely only to be a few units out and that it'd still run along and change heights without you really noticing much difference atall. ) As an example, the difference between 2 cars is pretty small. In my normal ride height, the sensor readings are about 122-124 and on a mates car, they are 124 - 125. Minimal difference.

Its then a case of plugging in a EAS programmer and re-calibrating the new sensor corner so that the ECU knows the right reading for the right height. To calibrate it, you just have the programmer running and tell it to raise or lower a step at a time until the wheel top <-> arch height is the same as the original you measured. The sensor reading of that measured height is then stored within the memory.

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Your stealer is ripping you off big time with those prices imho - to the point it would pay for your own Rovacom Lite at those prices.

Not far off...I just totted it up on Rovacom's web site - I make it £636.85 VAT for everything needed to do the P38a EAS (on the plus side it's the core bits that are expensive, so adding additional modules later is relatively cheap). If it's really going to be that expensive to get a garage to sort it, I'd be willing to go halves (it's £801.35 for everything to do the EAS for both trucks, so about £400 each). I think mine needs completely recalibrating (I want to raise the high profile height anyway) so it would probably be worth it.

I think you'll find local independents a lot cheaper, though. Most seem to charge about £40 'just to plug in the computer' - but that starts to sound quite reasonable next to the £100 you were quoted! :blink:

Suppose it comes down to how much you trust the EAS not to go wrong again - the Rovacom option might well work out more expensive this time, but next time it's already paid for.

In terms of backing up the ECU, that not entirely necessary imho either. The ECU shouldn't need backed up when you change a sensor.

The IT pro in me gets a nervous tick at the idea of tinkering with any computer system without backing it up first...but it shouldn't be necessary, and for £100 I'd take the risk...

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but what is there to back up?

As far as I could remember with the Rovacom, you had the option of backing up the height tables that were programmed into the EAS ECU which you could then restore from the PC back to the ECU . . . . but in your case, thats partly pointless since you'll be recalibrating the heights anyway with the new sensor.

I dont remember what else you could back up? I mean . . . what else can you program? ( other than reading / resetting error codes )

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but what is there to back up?

As far as I could remember with the Rovacom, you had the option of backing up the height tables that were programmed into the EAS ECU which you could then restore from the PC back to the ECU . . . . but in your case, thats partly pointless since you'll be recalibrating the heights anyway with the new sensor.

I dont remember what else you could back up? I mean . . . what else can you program? ( other than reading / resetting error codes )

Nothing that I'm aware of. I suppose there are other registers that you don't normally adjust (the boundary speeds for height changes, for instance), but they might even be hard coded in the firmware. Suppose there is backing up the firmware itself, but I'd have thought a dealer ought to be able to flash a new copy of the firmware if it gets corrupted.

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Now then Geoff that sounds like a very interesting proposition.... £400.... will have a think.

Anyway after a sunny afternoon in the gym car park (oh for a drive and a garage) I have found all 4 sensors are reading the same (9.91V or so), and as she is on the bump stops that seams reasonable.....

So gone is the idea of a faulty height sensor. So I ran the copmpressor for a further 5 mins and tried to manually inflate each bladder (C117 pins 1,26,(10,11,27,28)) each SOV clicked but no movement... are there any known components that fail reguarly between the compressor and valves, and is there a suggested way of testing them??

PS. These manual inflation valves as seen on ebay ( http://cgi.ebay.co.uk/Air-Suspension-Manua...1QQcmdZViewItem ) has anyone used or have comment on these?

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Anyway after a sunny afternoon in the gym car park (oh for a drive and a garage) I have found all 4 sensors are reading the same (9.91V or so), and as she is on the bump stops that seams reasonable.....

I guess to test this properly you really need to move each sensor through its full range while watching the meter - you could always disconnect the arm from the suspension in order to do this while the suspension is out of action. I'd be looking out for areas of zero or (more likely) very high resistance where the track is damaged.

Has anyone on here actually tested a faulty sensor? How did it behave?

If you do find that a height sensor is faulty they can be stripped and cleaned up, so may not need replacing - one of mine has been stripped before (by a garage, when they couldn't get a replacement) - I keep a couple of spares, but have never had to replace it.

So gone is the idea of a faulty height sensor. So I ran the copmpressor for a further 5 mins and tried to manually inflate each bladder (C117 pins 1,26,(10,11,27,28)) each SOV clicked but no movement... are there any known components that fail reguarly between the compressor and valves, and is there a suggested way of testing them??

Either you've got an air leak or your compressor is shot. If it's a leak, it's a big one, so a few minutes with a spray full of soapy water should be enough to eliminate that. You can find out whether your air tank is getting up to pressure by jumpering pin 1 (+12V) and 8 (compressor) on the EAS ECU plug and putting a meter from pin 13 to earth - this is the tank pressure switch and will go to 12V when the tank is up to pressure. It should take only a few minutes, but might take longer if your compressor is on the way out. From what you describe I'd guess it won't get up to pressure at all, but it's worth doing as it will confirm that the problem is in the compressor/tank area of the system.

Lots on compressor diagnosis and repair options here:

http://www.rangerovers.net/repairdetails/a...compressor.html

and here:

http://www.rangerovers.net/repairdetails/a...ebuildtemp.html

The rangerovers.net site is easily the best source for DIY info on the land rover EAS system that I've found anywhere.

PS. These manual inflation valves as seen on ebay ( http://cgi.ebay.co.uk/Air-Suspension-Manua...1QQcmdZViewItem ) has anyone used or have comment on these?

I'd have thought you're not getting a lot for your money... could probably put something equivalent together for a lot less? I don't have much idea what the components would cost, though, so maybe not. A few other options here:

http://www.rangerovers.net/repairdetails/a...on/replumb.html

Looks like the cheapest option is about £40 and not as tidy, so maybe it's not such a bad deal.

They do at least give you options if your compressor or tank are fubarred, which jumpering the connector doesn't.

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If it's not too late Beng, I can recomend ME to do the reprograming of the Range Rover Classic EAS system. I own a copy of Rovacom and I don't live to far from you I think.

And BTW the garage is talking pants. When you swap a height sensor the callibration in the ECU is wrong for that one wheel, so you need to recallibrate it. The original testbook sequence involcved taking the bump stops off and using callibrated block in their place and logging the height data, then inputting the same values as target heights. Rovacom makes it so much easier. I also like to have mine at non-standard height, it rides 1 inch lower.

In an afternoon I completely 'mapped' my suspension for future reference and reprogramed all the available height settings, now it takes me 5 minutes to reprogram the EAS to whatever I choose, towing, fast road, greenlaning.

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If it's not too late Beng, I can recomend ME to do the reprograming of the Range Rover Classic EAS system. I own a copy of Rovacom and I don't live to far from you I think.

Ben has a P38a, so unless you have the P38a EAS modules and ODBII lead it would mean adding those to your system.

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If it's not too late Beng, I can recomend ME to do the reprograming of the Range Rover Classic EAS system. I own a copy of Rovacom and I don't live to far from you I think.

And BTW the garage is talking pants. When you swap a height sensor the callibration in the ECU is wrong for that one wheel, so you need to recallibrate it. The original testbook sequence involcved taking the bump stops off and using callibrated block in their place and logging the height data, then inputting the same values as target heights. Rovacom makes it so much easier. I also like to have mine at non-standard height, it rides 1 inch lower.

In an afternoon I completely 'mapped' my suspension for future reference and reprogramed all the available height settings, now it takes me 5 minutes to reprogram the EAS to whatever I choose, towing, fast road, greenlaning.

Many thanks for the offer, not sure if the ecu is that different from the classic actually - serial comms i believe to tap straight into the ecu.

All height sensore found to be fine... tested the compressor.... no compression at all :-( Whipped it out and sure enough the piston ring had gone. Had a look at the motor contacts and they are pretty much gone as well, so I think a recon is in order, only problem, paddocks are out of stock. Anyone recommend a cheap recon place / similar compressor?

Many thanks.

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Many thanks for the offer, not sure if the ecu is that different from the classic actually - serial comms i believe to tap straight into the ecu.

All height sensore found to be fine... tested the compressor.... no compression at all :-( Whipped it out and sure enough the piston ring had gone. Had a look at the motor contacts and they are pretty much gone as well, so I think a recon is in order, only problem, paddocks are out of stock. Anyone recommend a cheap recon place / similar compressor?

Many thanks.

Try Rob at Foleys Specialist Vehicles on 01279 793388. He had a couple last week when I thought I needed one! He's a good bloke and should be able to sort you out...not sure how the logistics would work - He's in Harlow, Essex... but give him a shout!

Good luck... DD

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Many thanks for the offer, not sure if the ecu is that different from the classic actually - serial comms i believe to tap straight into the ecu.

It's not that different, but it's different enough - the classic system uses a proprietary extension of ODBI for diagnostics, P38a uses a similar extension to ODBII, so it's different leads and software modules for Rovacom.*

All height sensore found to be fine... tested the compressor.... no compression at all :-( Whipped it out and sure enough the piston ring had gone. Had a look at the motor contacts and they are pretty much gone as well, so I think a recon is in order, only problem, paddocks are out of stock. Anyone recommend a cheap recon place / similar compressor?

At least it's a straightforward fix, even if it's not the cheapest bit of the system.

*Technically, I think the ODB protocols only cover reading values from systems not updating them, so I guess from that point in it gets even more proprietary.

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It's not that different, but it's different enough - the classic system uses a proprietary extension of ODBI for diagnostics, P38a uses a similar extension to ODBII, so it's different leads and software modules for Rovacom.*

At least it's a straightforward fix, even if it's not the cheapest bit of the system.

*Technically, I think the ODB protocols only cover reading values from systems not updating them, so I guess from that point in it gets even more proprietary.

This is true however from what i have read the ECU is the same, so could in theory be swapped into a classic (could be very wrong there!?"!)

Anyway after a few phone calls I have sourced a brand new compressor for £120 which is installed and the system comes up nicely - see how she is in a few days tho.

And the big bonus is that I have found a garage that will reset the fault code on the ecu for £15 :-) - which seems about as good as I am gonna get

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Try Rob at Foleys Specialist Vehicles on 01279 793388. He had a couple last week when I thought I needed one! He's a good bloke and should be able to sort you out...not sure how the logistics would work - He's in Harlow, Essex... but give him a shout!

Good luck... DD

Good info, thanks... bit far for me tho - got that need to get her running feeling ATM

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  • 3 weeks later...

Does anyone know of a decent specialist in sheffield to clear my fault codes? DLS in Matlock said they would do it for £15, but finding a time to get to them is difficult.

Even though she appears to be in hard fault she still comes up onto air and loses the 35max after about 10 mins of driving - still no control tho.

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Does anyone know of a decent specialist in sheffield to clear my fault codes? DLS in Matlock said they would do it for £15, but finding a time to get to them is difficult.

Even though she appears to be in hard fault she still comes up onto air and loses the 35max after about 10 mins of driving - still no control tho.

That sounds like a 'soft' fault not 'hard', then - as far as I know the basic distinction is that a hard fault will dump you on the bump stops and leave you there (on the grounds that the suspension probably isn't safe to use), whereas a soft fault allows limited functionality.

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That sounds like a 'soft' fault not 'hard', then - as far as I know the basic distinction is that a hard fault will dump you on the bump stops and leave you there (on the grounds that the suspension probably isn't safe to use), whereas a soft fault allows limited functionality.

From info I have picked up a hard fault is the only fault that displays the 35mph max speed on the dash tho... could be wrong - would just be nice to regain control :-)

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