For the past 6 or 7 weeks Ive had the "HDC Fault - System Inactive" and "Suspension Fault" along with the yellow ABS and brake warning dash lights illuminated permanently on my dash along with a ream of bongs. Although irritating, this in itself has not been a problem as my motor has been driving fine......until today!!

I headed out and got no further than half a mile before BONG and a suspension fault and speed warning 30mph max appeared on the dash. As usual I was yeah whatever, until I headed out onto the main road. As I picked up speed the motor was bouncing about like it had no shocks so I stopped and when I jumped out I discovered that the suspension had decided to s*!t itself and drop onto the bump stops, so I spun around and very gingerly returned home.

Got home, plugged in my newly acquired IID tool and there were a multitude of faults, the majority to do with the suspension, funnily enough, however another fault code was U1026-87(2F) - lost communication with steering angle sensor module - Bus signal/message failure - missing a message, so first I recalibrated the steering wheel, cleared the faults and out went the HDC Fault message, the two warning lights and the centre console lights for the suspension came back on again. BIG PAT ON THE BACK FOR ME, or so I thought

Ignition off, ignition on and....BONG....Suspension Fault and out went the height adjustment and special programs wheel lights but no dash lights this time so I jumped out to check the suspension and it was slightly back up off the stops but still lower than access height and when I checked the IID tool I found the following faults :

Click image to enlarge

"as I have always had intermittent Suspension Fault and Vehicle lifting slowly fault warnings since buying the RR just over a year ago."

Don't blame the fatty, it's been telling you for a year that it had a problem, if you ignore them, they tend to get worse...

Maybe start with the compressor and system vent and take it from there...  Pete

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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Yup pretty amazing it’s been going well for a year. I do think the bum gauge ometer is differently calibrated for different people as I’m very sensitive to these things. I notice it immediately in mine, and even in my daughters evoque I noticed it when we were buying it and the owner said it rides fine.

It could be just the compressor, but as you e been ignoring this for a while I’d suggest you’d take it to a specialist and get it properly looked at.

I had the “filling too slow” message for ages and replaced the compressor twice but finally tracked it down to a hole in the reservoir tank, which was replaced and all is well.  Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

Last edited by alanm_3 on 10th Dec 2021 10:09am. Edited 1 time in total

Probably had a leak somewhere for a while and your compressor is now past its best and finally thrown its hand in, try find the leak, try running the compressor and checking the output.

The first fault suggests that the brass exhaust filter is blocked, which is easily fixed with a small drill bit. The other faults suggest that the compressor has problems of which there could be several causes.

Thanks for all your replies guys, they’re really appreciated Here’s a quick update……

With the help of my new IID tool I managed to clear all the suspension faults and the compressor began running again. I lifted the cover off the unit and immediately heard a slight hiss so began checking the compressor connections. The pipe arrowed in the photo appears to be letting air out and moves quite freely and when I first moved it slightly a puff of white dust came from it.

Click image to enlarge

Click image to enlarge

If you do go down the replacement route only fit the AMK unit, I fitted a cheap Dunlop and it only lasted 16 months

Once inflated the suspension should not deflate even if you disconnect the compressor. I would suggest the issues is with a leaking suspension bag or pipe or valve block. 2012 TDV8 Vogue (L322)

Thanks for that info JayGee because my simple mind was thinking that a leak at the compressor would also cause the suspension to drop. The previous owner replaced the reservoir below the drivers side so I suspect that there must have been a problem then.

If I can pick your brain a bit more, once filled, how is the air retained in the airbags if I can disconnect the compressor but not lose height? Is that what the valve blocks in the wheel arches control? Current collection :

2007 Vogue TDV8 Stornoway grey, black on black
1982 JCB Sitemaster (resto)
1970 MGB
BMW R1200GS

I'm no expert on this but .......as you can change the compressor and the system doesn't deflate there are valves as well. These regulate normal height changes and the pump keeps the reservoir full. The pump itself can't generate the large volume of air necessary for say going from access to offroad quickly and the reservoir does this. Unfortunately there are numerous places for the system to leak. The GAP IID tool will help identifying a faulty compressor or valve but not a leak. Your ear and some plumbers gas leak fluid/spray will help. Plenty of info on this forum via the search function 2012 TDV8 Vogue (L322)

As I mentioned above, mine turned out to be the reservoir. I also changed the valve block on the O/S rear, which ultimately wasn’t my problem.
I also had the “vehicle raising slowly” message and it would often take about 5 minutes for the car to raise.
Get yourself some soapy water in a spray bottle and start looking for bubbles. Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

Thanks alanm_3, once I get the compressor rebuilt and the sensors changed that'll be the route I'll be going by the looks of it Current collection :

2007 Vogue TDV8 Stornoway grey, black on black
1982 JCB Sitemaster (resto)
1970 MGB
BMW R1200GS

It would be a quick check for the reservoir. It runs from front to back under the N/S cill, a liberal spray of the soapy water will produce lots of bubbles if it’s leaking, much quicker that changing valve blocks etc.
it was the last thing I thought it could be but when I removed it, it was so rusty, I was amazed it still held any air at all, and given your location and age of car, there’s a good chance yours will have been subjected to the same weather as mines. Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

It was replaced about 6 or 7 months before I bought it and still looks like new so its not the reservoir. Soapy water, patience and several cups of tea it's going to have to be Current collection :

2007 Vogue TDV8 Stornoway grey, black on black
1982 JCB Sitemaster (resto)
1970 MGB
BMW R1200GS