Disco 2 Air suspension won't lift after sensor change

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Larry365

Active Member
Posts
558
Location
Lincolnshire, UK
Afternoon

Swapped both sensors on the D2 after one was faulty. I have done it many times before on other discos with no problem. Done properly, battery d/c etc.

The disco will not lift. Using donor vehicle I've done the following.

Driven the vehicle back and forth over bump
Jacked it up, lowered it down.
Replaced valve block
Replaced pump
Left battery dc overnight
Started and stopped engine quickly
Bypassed relay (pump runs)
New relay
Checked fuses (only 2 right??)
Check all connections (air and wire)
No leaks

Lower left SLS warning light always on
Lift light always on
Pressing lift button once, nothing happens
Hold loft button, 3 chimes nothing
All doors and bonnet closed and confirmed

The system had over inflated prior to sensor change so all air was drained from the system before sensor swapped. By bypassing the relay I was able to out some air in the system but not enough to support itself. I kept it running for 3 or 4 mins but I'm pretty sure it was pumping against a closed valve block.

Any help would be great. We are working in Croatia, limited to parts and no local diagnostics. Worst case we will get springs but would prefer to keep air
 
As long as the warning lamp is on you might not be able to fix it without diagnostics cos if it overinflated before it's very possible to be a "compressor duty cycle exceeded" code logged then the system will not start untill the code is cleared.... As long as there is no leak present you can improvise a wiring as to inflate the bags by giving feed to the compressor and valves then let them unplugged and it will stay on level for weeks or untill you caf fix it...or eventually find some schrader valves around there... read this: https://www.landyzone.co.uk/land-rover/air-suspension-fixed-itself.342677/#post-4494410 then scroll down to post 15
 
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Great. Thanks for the info, at least we know what the issue is. Is there no way to clear them manually? shorting the terminal wires for example. It is a 2004 D2. Do you know if this is OBD2 compliant? Can any diag tool be used to reset the codes or does it have to be land rover compliant? Cheers.
 
It has to be Land Rover compliant scantool... some decent multivehicle tools which have the D2 in the coverage list can work with the SLS too but generic OBD2 is useless
 
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It has to be Land Rover compliant scantool... some decent multivehicle tools which have the D2 in the coverage list can work with the SLS too but generic OBD2 is useless

We found a guy with "decent" diagnostics. He was able to ready most codes, live data get readings of the height sensors etc but was struggling to delete codes and he basically gave up. About an hour later, I jump in the car and the SLS light and lift light have gone... I thought maybe he cleared them without realising but still nothing happens. Pressing the lift button chimes 3 times but no light and obviously no movement. I went through the procedures to trigger it to wake up but nothing. I now have a feeling he has accidentally wiped it completely (the same procedure when you convert to coil) What are your thoughts? If that is true then it helps confirm our choice to convert to coils. We contemplated buying a cheap LR reader/code clearer but If my suspicions are correct, that probably wont fix the problem if the car doesnt even know it has SLS.
 
After owning a D2 for 9 years it is my definite opinion that unless you have bottomless pockets a decent D2-specific diagnostic tool is essential. I still have the nanocom 1 I bought in my first couple of years and it must have saved me many hundreds of pounds.

Without one you're shooting in the dark.
 
If it was accidentally set for coils in the ECU this is reversible any time... some multivehicle scantools have the D2 SLS in the menu but they dont work 100% well with it... i'm an opposant of coil conversions so i'll never advise you to do that cos the system is not very complicated as long as the proper diagnostoc tool is used, you can inflate the bags any time as i've already explained and ride it so long time
We contemplated buying a cheap LR reader/code clearer
unfortunately there is no such thing as cheap and good LR tester, those which are cheap dont work well
 
Yeh fully appreciate what youre both saying. I personally am an advocate for air suspension too. Always repaired it on my previous discos and keep it going on my own D3. The D2 we are discussing is a friends and ergo its not my decision. They are here in croatia all year round and I have to leave them here in a month and the only land rover service place is a genuine dealer in the capital 4 hours away.

Nanocom it is then?
 
Nanocom will pay for itself in no time if somebody wants to keep the D2 for himself... main dealers have no more experience with D2s or other older LRs or if they have they dont care about them
 
Rather than change to coils get some emergency inflation valves from fleabay here
https://www.ebay.co.uk/itm/DISCOVER...L-INFLATION-BYPASS-4MM-OD-VALVES/282534767304
and until you can resolve the issue just connect them into the airlines to the bags and inflate with an tyre air line until you are happy with the height. At least you keep it working and can solve other issues in your own time.
Several have fitted them with inline on/off valves as well so you can turn off the air supply from the pump (in the event of pump or valve failure), and then re inflate just with a tyre airline to your desired height. At least then you have the ability to clear the faults/reset the system at some later stage, while still benefiting from air on the rear.

As Fery said, the cost of a Nanocom will pay for itself very quickly, almost essential if you have a D2. There are other makes as well, Hawkeye etc...

Tony
 
Cheers. I saw these in the other thread. I think we'll get a couple. We're in the process of getting a Nanocom which as you say will pay for itself in no time and given we can't find one anywhere in Croatia, it might help others out in the future too. (Will be updating my info on the Landyzone map).

Unfortunately it looks like Nanocom won't ship to us in Croatia as we need to get vat back in the uk.. so it's gonna be posted from Cyprus to the UK and then back down to Croatia o_O
 
Our Nanocom arrived today but we don't seem to be having much luck resolving the issue.

With the car sat on its arse, the sensor readings are 66 right 254 left (does not seem right)... We jacked the car up to roughly 480mm from hub to arch on both sides. Sensor readings 112 right 254 left). We then inflated the bags via calibration (simply using "sls pump "on"" will inflate the bags slightly but will not lift the car). We pumped until the car was supporting its own weight at 480mm and apply settings. The car is now sitting perfectly level using air, no noticeable leaks. Wait 60 seconds and then turn ignition off and the car immediately releases all air from the system! Both sensors are new. Voltage readings are 4.9v right and 5.1 volts left.

Are we doing anything wrong? Obviously left sensor reading is bad as maximum is 255. I have another new sensor and I am wondering if the left one is new-faulty. Why is the car lowering when ignition off? Changing target values doesnt seem to do anything; either they cannot be reached or nothing changes. Starting car, no action from pump. No errors or lights. Lift button in cab does nothing.

Thanks
 
It drops due to that too big difference between the sensor readings corroborated with the differennce from the stored target heights

Swap the sensors around cos then they'll work on the other half just to rule out the sensors and if the fault stays the same the most common is a contact issue in the plug on the side which is missreading hence this well sold kit: https://www.ebay.co.uk/itm/Discover.../151466538011?_trksid=p2349526.m4383.l4275.c1 but can be a wiring issue too on that circuit... cheap aftermarket sensors can be bad on arrival

if you have nervs read the whole thread from the following link to see what a saga due to faulty new sensors(even though the problem was kind'a the other way around) but here's the gist of it: https://www.landyzone.co.uk/land-rover/sls-no-lights-and-wont-go-down.334315/page-4#post-4332624 ...reading that whole thread will give you many good hints for troubleshooting
 
Yeh, bloody hell its sorted. Obviously..... OBVIOUSLY.... I just hadn't plugged one of the sensors in properly. Nanocom was still needed for calibration anyway plus we definitely need one out here in the Land of no Rover. I'd like to think there was more going on originally than simply a incorrectly fitted sensor. Thanks for you help mate. Front suspension as per your recommendation going in later this week. Very happy.
 
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