eas fault all lights on p38 2.5dse

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OK. I'm not an electronics expert but ...

If you remove the exhaust valve from the EAS then it'll make a sound like a truck air system everytime it dumps air. Can you hear that air dump?

OK. Just opened your spreadsheet. I've changed it a little so I can see things a little clearer. Looks like the rear-right (RR) was too high right from the start compared to target height. The RR valve and exhaust were allegedly open pretty much from the start. Around line 70 it gives up on the rar being too high and concentrates on the front being too low so it shuts the back bags and opens the front ones with the exhaust shut. Height comes up so all OK there. Strangely the rear ALSO comes up! Then it goes back to try to drop the rear bags back down. This time it responds (line 86 ish). 80 - 160 it seems to be fighting to keep those front bags inflated. Around 170 the back rises with no valves open! By 180 it is fighting to get the rear back down again. Have you got helium in the boot? Around 336 it ties to go to motorway height = LOW PRO. Oddly enough front-left goes down with no help and front-right isn't far behind. WAMMERS: is this possible without a leak? Then it goes back to trying to drop that RR bag. Around 400 it not only responds but overshoots! Around 400 the rear bag mysteriously inflates! Car tries to get it back down again but it is fighting the helium balloons in your boot! Really a dodgy height sensor? I have no idea what the ECU WAKEUP part is doing. Reset to standard values?

Is it possible to go up with no valves open? I'd think either dodgy height sensor OR the valves are opening on their own without the EAS computer telling it - dodgy wire from driver pack to valves, maybe? If you can hear the exhaust actually dumping with the filter off then we'll know if it is actually being activated.

That said, I'm a complete novice just trying to interpret your figures. I think Wammers needs to advise if the scenario is physically possible and then maybe DataTek will know better what the electronics are actually doing.

My workings attached. Just makes it clearer for me to understand but might help. View attachment EAS01a_Logs+Chart_20140616.zip
 
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No was actually on inside lane, keeping the noise down because I was on conference call !!

The reason I posted earlier in this thread about adding suppression capacitors to Driver Pack Inputs, was because I wonder if the valves are both randomly opening & closing contrary to what the ECU thinks. The Logs only show the ECU's view of the system. I noticed that somebody posted elsewhere, that the driver uses Comparators & Mosfets, which are both susceptible to HF glitches on the 12V switching signal, and possible the 12V supply. Bad earthing & compressor motor interference could also cause issues.

When I get a chance I will put my Scope on the Input & Outputs, Motor power & 12V Supply lines to check what they look like for noise.

The "ECU Wake-Up" is probably me clearing the fault while driving. . . .remember Nanocom resets the ECU when you enter & exit the Inputs screen.

Also, will look at your Excel version tomorrow . . .

Thanks,
Pete
 
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pwood999 said:
Some more EAS data for anyone that likes Excel. . . .(see attached). . .. and does seem to point toward dodgy Driver Pack.

Today on way home from work I connected Nanocom again, and started logging. About 12-14 mins into the journey the height switch started flashing high-mode again . . . so the random changes do occur with EAS in diagnostic mode :)

Reset the EAS while driving at 65mpg (yes I know - naughty) and the EAS returned to normal.


So looking through the log file, I found something interesting. (approx. lines 440-680)
  • Rear Right sensor showing 10% above target height.
  • RR valve & Exhaust valves open . . .BUT height not dropping.
  • Definitely sounds like Driver Pack failing to actually open one or both of the valves. . . .
Assuming one second per data set logged by Nanocom, this is about 12 minutes after I started logging, which is quite close to when it happened.

Another question: I'm wondering why the values for the Rear Left height sensor are significantly smoother that the other three ?

Pete
Click to expand...
It's gone to wading height but it has not gone into hard fault mode and i don't believe it will when in diagnostic mode.
 
pwood999 said:
No was actually on inside lane, keeping the noise down because I was on conference call !!

The reason I posted earlier in this thread about adding suppression capacitors to Driver Pack Inputs, was because I wonder if the valves are both randomly opening & closing contrary to what the ECU thinks. The Logs only show the ECU's view of the system. I noticed that somebody posted elsewhere, that the driver uses Comparators & Mosfets, which are both susceptible to HF glitches on the 12V switching signal, and possible the 12V supply. Bad earthing & compressor motor interference could also cause issues.

When I get a chance I will put my Scope on the Input & Outputs, Motor power & 12V Supply lines to check what they look like for noise.

The "ECU Wake-Up" is probably me clearing the fault while driving. . . .remember Nanocom resets the ECU when you enter & exit the Inputs screen.

Also, will look at your Excel version tomorrow . . .

Thanks,
Pete
Click to expand...

Driver packs are working fine in thousands of P38's, I see no good reason to try to bodge a faulty one. Adding suppression will alter the characteristics of response.
Personally I can't see the point of going so deep in diagnostics, when mine had random height rises last year, I just swapped the driver pack and the problem went away. When I first got the car it did a similar thing due to a faulty height sensor.
Bad earths on the iner wing between the EAS box and the air filter also cause the same problem.
 
Datatek said:
As it's gone to wading height it's a soft fault, next stage it will drop to the bump stops and go to hard fault. Diagnostics is the only way forward. PM me for details.
Click to expand...
Hiya Datatek

How do I PM you, because I have now got the same fault.

It started off with the formidable BEEP, BEEP, BEEP, But it would still drive. Then all four lights on the ride height switch came on, and stayed on. Then the Little Car on the Dashboard, with an arrow. Ride height was very high, and now, its down on the bump stops, sat, more or less, on the tyres !!!
 
AMSCERP said:
Hiya Datatek

How do I PM you, because I have now got the same fault.

It started off with the formidable BEEP, BEEP, BEEP, But it would still drive. Then all four lights on the ride height switch came on, and stayed on. Then the Little Car on the Dashboard, with an arrow. Ride height was very high, and now, its down on the bump stops, sat, more or less, on the tyres !!!
Click to expand...
Envelope symbol top right of the page.
 
AMSCERP said:
Hiya Datatek

How do I PM you, because I have now got the same fault.

It started off with the formidable BEEP, BEEP, BEEP, But it would still drive. Then all four lights on the ride height switch came on, and stayed on. Then the Little Car on the Dashboard, with an arrow. Ride height was very high, and now, its down on the bump stops, sat, more or less, on the tyres !!!
Click to expand...

Hello and welcome to the funny farm:D:)
have a read throw this guide
https://www.landyzone.co.uk/land-rover/checking-eas-compressor-and-diaphragm-valve.172555/
 
pwood999 said:
Today during round trip to Ferndown (185miles), I had the "random high mode" about 5-6 times. Four times I managed to press the down switch in time and avoided the fault mode, but twice I missed it, and EAS went into fault mode. Reset each time with Nanocom & continued journey.

So for the last 50 miles I thought, lets try data logging on the Nanocom and catch the fault. . . . . . no further problems . . :confused: so my wife says "just connect it when you drive !

Does Nanocom usually prevent EAS faults while connected ?

History:
Already bypassed the white connectors in left footwell:- soldered joints instead of green corrosion.
Connectors in engine bay look good. Still need to check sensor connectors.
Compressor seals & piston seal replaced 3 weeks ago:- good pressure before & excellent now.
Replaced all seals in Valve block yesterday:- no more leak from exhaust outlet.
All height sensors give similar readings on Nanocom at all height settings. . . might be glitchy, but does't look like it on Nano.
------------------------------

I now suspect driver pack strangeness but being an electronics engineer, I want to investigate rather than part-swap.

  1. So, firstly does anybody have an internal diagram for driver pack ?
  2. Are the 12V switched inputs from ECU filtered for vehicle noise ? (maybe the capacitors have dried out)
  3. Do the height sensor inputs to ECU have sensible low-pass filtering ? (I'm sure the ECU does not need to know every small bump on the road)

My thoughts are to start fitting additional capacitors to the ECU & Driver Pack inputs to remove random vehicle electrical noise. Many years ago I designed a variable wipe system form my old XJ6, and you would not believe how random the wipers were until I filtered the electronics properly.

BTW, In case anyone finds it useful, I just uploaded the Land Rover "EAS - System Information Document" I found on Nano forums, to the EAS sticky section in How-To's.

Pete
Click to expand...
Did you change the air dryer ? sound's like a white powder issue valve block sticking open.
 
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