Hello All

Hope someone can help me. Since replacing all the front suspension bushes and joints including new struts & air bags I've been getting random faults.

It would frequently warn me I was going too fast for the off road ride height even though I wasn't at the off road ride height.

These warnings would occasionality be followed by Air Suspension Inactive. which I would then have to clear with the IIDtool.

I would also get other weird stuff like the compressor turning on & off every few minutes even when parked up. This went away after I pulled out the compressor relay for a few hours.

Now the latest fault the front suspension won't pump up but the back end goes up OK. The level indicator on the switch shows it as being at normal ride height, however it wont pump up to the off road setting or drop to the access setting. The front stays completely slammed whilst the back end is up where it should be.

I've tried everything I can do with the IIDtool & I've also tried disconnecting the batteries (it has 2) for a couple of hours but this didn't help. If I drive it like this I get the Air Suspension Inactive fault which clears OK the IIDtool doesn't show any other EAS faults.

I've checked the front level sensors are still attached which they are.

My current thinking is that the Air suspension module has failed.

Any advise gratefully received & if someone can tell me where to find the module it would be great.

Cheers....

Have you checked that the front level sensors are the correct way round. It's not unknown for them to reverse themselves particularly when the suspension has been extended past its normal limit such as when changing airbags?
An air compressor coming on regularly usually tends to suggest an air leak.

Hi, No I haven't checked that but until these last few days it's been running at normal ride height. I'll check it out though. Thanks.

Nobody else with any idea whats going on here?

Maybe someone can tell me where to find the suspension module?

Download the workshop manual from the wiki (link top right)

This has ecu locations and is worth a read.

The wheel height sensors usually only move a small amount during normal use, jack the fatty up and the sensor wipes across parts not used often, this can cause them to read incorrectly...

Maybe worth using the IID to show live values from them and manually move them to check they are working correctly, you will have to remove the arms from the suspension to do this... The readings will not be the same for each sensor, the value is just a number and relates to nothing, they should rise and fall smoothly though...

It's the only thing I can think of that would be disturbed during the repairs you mention but may be wide of the mark...

Seems too much of a coincidence that the ECU would give out at the exact same time you did the work...  Pete

__________________________________________________
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-

"... jack the fatty up and the sensor wipes across parts not used often, this can cause them to read incorrectly..."

According to the workshop manual, the height sensors use the Hall effect - so a magnet and a coil. So no wiping goes on, unlike the transfer box motor sensor ...

Oh right, well I know they don't like being messed with, had several fail on my old fatty when they had had a workout, I presumed the why... obviously something else upsets them..  Pete

__________________________________________________
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-

Can you get actual fault codes from the diag? Apologies if I've missed it but that's only the dash display or using the tool to clear which I wouldn't imagine is the limit of information available.

The IID gives a lot of information as well as fault codes... Pete

__________________________________________________
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-

Thank you everyone for your input. I'm pretty sure the fault is related to the work I did as interment faults & warning started showing up after I did the work.

I also feel confident the its an electronic/sensor problem as the back end pumps up no problem & the compressor stops & starts as it should with no sound of air leaks which I did have when one of the old air springs blew.

It's just been this last week or so it has started refusing to lift the front end up. I've tried forcing it up with the calibration function in the IIDtool but it doesn't budge at either side.

Any chance it could be a blockage somewhere?

Anyway I'll get back to it later in the week with my fingers crossed.

Cheers & thanks to all once again.