Hi.

For a little while, shortly after starting off, I received the dreaded 'Bong' sound, followed up by, 'Suspension Fault. Normal Height Only' message on the dashboard.

From other posts here, it seems this message is not exactly unknown, and replacement of the air compressor effects a cure. So a new compressor was ordered.

Here, I should mention the vehicle is MY 2007, and has the Hitachi compressor fitted.

Having fitted the replacement compressor, I am disappointed to find the situation is exactly the same. Same 'Bong', same message.

I do have the Gap IID tool, and after having cleared the previously stored faults, the fault log now shows;

'RLM-Suspension
• C1A20-64 (6C) Pressure increases too slow when filling reservoir - Algorithm based failure - signal plausibility failure'. Which if I've interpreted this correctly, means the system is reporting that the pump is not pumping enough.

The vehicle does not appear to 'lose' height overnight, or indeed over weeks, so I don't think there is a leak anywhere.

I see that the pressure in the 'Gallery', (is this the reservoir ?), is shown as being 39.2 psi, but I have no idea if this is significant.

Of course, there is a possibility the new replacement pump is faulty, but before I complain to the supplier I would like to be certain.

So, does anyone have any suggestions as where I should look next to find the fault, or is there a diagnostic procedure available somewhere? I have searched for one, including on TOPIx without success, but perhaps I missed it somewhere.

Any advice and suggestions will be appreciated.

Regards.

Mike

I had similar, replaced compressor and still had issues, ended up being a corroded resovoir and the pressure sensor attached to it was dying. Removed resovoir and it was full of rusty water. Replaced it and it's been fine since

Just checked my resovoir pressure and it's 187psi..usually if it's the compressor it will give you a pressure static when filling fault codes if the compressors failing..

You will enjoy removing the reservoir, and the valve block that has all the sticky bits that once unstuck do not stick back again. If you don't want to remove the reservoir, first port of call is the pressure sensor, located at the rear end. .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
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Hi.

Thank you both for your responses.

Fortunately, battling with the valve block under the vehicle is not applicable here, as the valve block is contained within the compressor housing, together with the reservoir pressure sensor. The reservoir itself is still underneath though, and has only a single pipe connected. (I invested in some TOPIx time this afternoon, to find this out.)

So I think my next step is to check out the valve block as best I can, though I suspect substitution will be the real test.

Thanks again for your thoughts, and I will post an update, when I've had a chance to take a look, which will have to wait for a few days as management has a few other jobs lined up for me.

Regards.

Mike

Hi Mikey32, did you manage to get to the bottom of this, as i have the same issues Tdv8 vogue
2008
HSE 4.0 v8
2001

Hi.

Sorry, I should have updated this thread. My only excuse is other time pressures.

Which is very poor link into the topic here.

The problem was indeed the reservoir having rusted away at its front end.

Others have said you can hear the air coming out. I couldn't, probably due to to the size of the hole.

Anyway, reservoir has been changed, and the suspension goes up much faster than it did before, so I guess it had been leaking for a good while.

My thanks to Dan at Duckworth for supplying the replacement so promptly.

Good luck with finding the problem with your FF.

Regards.

Mike

My car is the same age and model as Mikey 32's, and I seem to have a very similar problem.
For a little while, shortly after starting off, I also get the dreaded 'Bong' sound, followed up by, 'Suspension Fault. Normal Height Only' message on the dashboard. The lights are then out on the height adjustment switch which is presumably "Fail Safe" as shown below. Turning the car off and restarting usually gets it working again.
When the system is working, the car goes up and down, but it does it very slowly.

I've plugged in the GAP IID tool, and got the following reports

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I had the same problem with the 'noisy' signal from the front left corner. I changed the height sensor and it's been fine since with a nice flat line on the IID tool.

Mind that's not been the end of my issues as it looks like my compressor is on its way out too and possible valve block issues.

I replaced the corroded and leaking reservoir at the weekend, and hey presto, all is well again. Thanks to Mikey32 for the heads up and Dan for the quick despatch of the new reservoir. A straightforward job that was quite inexpensive so happy days.....

Having just read the above post (one of many) about the air suspension.

It occured to me that maybe a better solution than moisture crystals to avoid getting moisture in the system, is to do exactly what a factory layout that has compressed air on tap does.
Namely, to add to the circuit a moisture trap, that periodically can be drained (they are usually a glass bowl with a draincock at the bottom). Some members have found, when replacing their reservoir that its partly filled with water, also what about a displacement lubricator in the circuit as well ?.

I wonder how buses, coaches and lorries manage.

Just a thought guys

Just a thought for you guys, you mention your old compressor is an Hitachi, they did change to a different make compressor for some models, if you have changed the compressor manufacture then you need to do a software update

Had all these issues myself changing the compressor on a mates sport thing