Air Suspension has me Stumped

[Hawk in WY]

I am committed to restoring the eas on my 1994 LWB Classic. Spring advocates need not reply.

I have replaced the air bags and ride height sensors with new parts and the ecu with a used part allegedly from a truck with working air suspension.

I recently resealed the valve block.

The suspension came up to ride height immediately with the new valve block and worked fine around town.


After driving over 55 mph for around 5 minutes, the suspension slowly dropped to the bump stops or with minimal air in the system. This happened with an earlier valve block and i replace the delay sensor. Error message was "Exhaust value permanently closed." I cleared the error, but the suspension stayed on the bump stops on restarting. Would not respond to the up or down buttons.


I checked again and no errors were found. I cleared again and still on the bump stops. After a few minutes driving the suspension came up again, but then dropped again to the bump stops after driving over 55 mph.


Stopped, checked again, no error messages, cleared again. This time left side came up, right side still down.


No error messages. Drove with a list to starboard for maybe five minutes, below 55 mph, and it eventually leveled out.


I got the "Exhaust valve permanently closed" only once. Clearing the error did not allow the suspension to reflate.

Any suggestions of where to look for the remaining gremlin much appreciated.

Thanks in advance.

New information: On start up top and bottom lights illuminated. Believe that indicates a soft fault. New error message: "Pressure sensor not changing state. Always on." Never seen that one before.

Cleared the fault. Suspension comes back to normal but do notice light on the down button blinks for a very long time when suspension lowered which I believe indicates compressor still running which supports weak compressor.

All suggestions welcome.

[o2batsea]

In the metal box under the truck is an electronic box that has a bunch of wires going out to various connectors. This is a steel tub with all the electronics potted in what looks like bitumen or some black epoxy. Some of the ones I've seen have been compromised in that the steel rusts allowing water into the guts. When that happens you get all these random faults. If it were me, I'd be swapping in another and trying it all again. If you need one let me know.
Elsewise you have a bad solenoid (or several) in the valve body. Usually not a failure point but have seen it.
I am assuming that you are using Storey Wilson's EAS Unlock software.

[Hawk in WY]

Thank you for helping out.

Using EAS Kicker. Primitive, but does the job.

Swapping in a rebuilt compressor since the current is 21 years old.

I thought the EAS ECU was under the left hand seat.

Where is the metal box you're recommending I replace?

[o2batsea]

Under the right hand side of the truck there is a box that has the compressor and valve block inside. The 'lectrickery is in this box behind the valve block. The other thing that can cause headache is the waterproof multi plug, which ain't. Clean contacts and reseat.
EAS ECU sits on top of the engine ECU under the right hand seat.

Try my brand:
http://www.rswsolutions.com/index.php/range-rover-classic

You can't get the plastic 5 pin plug any more, but there is a workaround.