EAS Pressure switch replacement (ANR3902)

I've had a long running "soft fault" with my EAS for about 12 months. Twice I've had to have the EAS fault reset but I didn't get the speed warning. The local independant I took the car too said he was getting a fault with the pressure switch ANR3902. I bought one of these about 6 months ago and thought I'd change it out next time the fault came back. The early warning signs that it is going to flag up an EAS fault again are that the suspension goes up to the top setting for no reason whilst driving, this has happened 3 times in 2 days so the EAS fault is immenent. I believe the pressure switch is located on the main valve block, so my question is how do I replace it? I assume I need to depresurise the system, is this possible manually or do I need software? Also can I get access to the valve block without removing it?
I' have also read on Rangerovers.net that other causes of "soft faults" are bad connections and faulty relays, I work with electronics and it does have the symtoms of a faulty connection although I never seem to get the fault in the summer months, so could be a cold thing.
Any help appreciated.
Mick

Unfortunately the Pressure switch fault is rarely actually the switch. Its normally a worn compressor or the driver pack. The EAS ecu has a set time that it expects the tank to fill and if the tank has not filled due to a worn compressor the ecu returns a pressure switch fault instead of a compressor fault. The next time it faults hop out straight away and check if the compressor is hot. If it is very hot then it is likely that the compressor is worn out, if it is cold it is more likely the driver pack, the fact that your car is going up to the extended height for no reason it is more than likely the driver pack that is giving trouble.

Cheers SpudH,

What is the driver pack?
Thinking back the original fault diagnosed by test book was "over pressure fault". I would imagine that the pressure switch controls the pressure and therefore the compressor running so thats probably why this was suggested.

The driver pack is the little magic electronic box (I'm a civil engineer so anything to do with electrons is a mystery ) that actuates all the valves. Its a pricey bit of kit, I don't have the part no, but Shupack from roverrenovations in the states sells them refurbed. Check out his website for anything to do with EAS.
You might be right about the pressure switch in your case but with the car changing height without reason is a symptom of driver pack problems (mine does the same, as I already had a kicker I never replaced the driver and just reset the suspension everytime it faulted out, not ideal but I've managed. When funds allow I'll replace the driver)

Cheers SpudH.

I'm thinking about buying a cable to let me reset it incase it comes back and downloading that freeware software.

Do you know if changing the sensor is difficult? It will be connected to the pressure system so that will need depressurised, is there a way to do that without using testbook?

Looking at rave it seems straight forward but i would imagine removing the valve block would be necessary

Started looking through the explination of how the suspension works in Rave.
The bags can only inflate if the solenoids controlling them are operated, if my pressure switch was faulty it would cause the compressor to run but how should it affect the height?
I'm starting to think there could be an issue with either a relay or a bad ground connection somwhere, causing the EAS control unit to put the vehicle into the highest setting. Think I'll get the wiring diagrams out over the weekend and see what I can find. I'll post back any findings that may help someone else.

I don't think the 2 are related. Like I said the pressure switch rarely gives trouble.
The driver pack can do funny things, if you look back through the posts you'll come across descriptions of RR's 'dancing' at traffic lights and things like that. Settling down when parked on unlevel ground is another one which can be driver related (that is if you've not got leaks!) If I unplug the EAS mine will not drop a bit over night when parked on uneven ground but leave it normally and it will often be on the stops in the morning. You should check out blackbox-solutions website for description of the EAS fault codes and what they really mean. Also definitely go to roverrenovations.com they specialise in EAS and have a great website.

micko2602 said:

Cheers SpudH,

What is the driver pack?
Thinking back the original fault diagnosed by test book was "over pressure fault". I would imagine that the pressure switch controls the pressure and therefore the compressor running so thats probably why this was suggested.

Click to expand...

If the actual wording of the fault was "Pressure signal constantly high" then you can be sure its the drive pack failing.It is part # ANR3900 - about £170 + Vat retail.

Thanks eightinavee ans SpudH. I've ordered a cable and hopefully if the fault re-occurs I can find out exactly what it is.

I've got the pressure sensor anyway so I was going to fit it, seems a waste of money having it and not usin it.

Update:
Went through the wiring diagrams to see if there could be an earth fault all looked ok. Decided as I had the replacement pressure switch to swap it out. Found that it had been replaced before, the wires had been soldered to the original cables. Also there was no thead tape or loctite on the threads so there would be some leakage from there, and what appears to be a pressure relief valve next to it had no tape or loctite on it. Doubt these would cause any problems as such but thought I'd do it properly anyway.
So new pressure switch is fitted and waiting to see what happends next! Got a cable from ebay and downloaded the software so should be able to reset any future faults.

Did this fix your problem? or did you replace the driver too?