I was just driving home and a red alert came up and it said 30mph max. The car was bouncing around like a loon.....made me feel sea sick Pulled over, engine off, started up again and it drove ok but the symbol was amber this time. Parked up at home, turned back on and no alert???

It was this one...




Could it be the filter underneath the driver side again? Maybe it needs changing. I`m only saying that as last time I had the amber warning, the guy I bought it from took me to a Landy garage and that`s what he fiddled with. Steve.

He might have been bleeding the system rather than changing the filter. If the filter needs changing so often then there's something more amiss.

First thing, as always, is to have the codes read. Also check the fluid level in the reservoir with the system cold.

The problem with Dynamic Response errors is that it could be one of a number of things - from a ride height sensor to steering angle sensor/calibration to something else. Codes are essential as a first step in figuring it out. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

No...all he did was tap the unit with a small hammer and use some electrical spray. He said they can get blocked and a light tap usually sorts it.

Reservoir level is ok....checked that and others earlier after I washed it. Steve.

Evening Cymruambyth,

see extract of suspension section below. hope it helps. do you have a code reader?

Fault Detection
The air suspension ECU performs fault detection and plausibility checks. Fault detection is limited to faults that the ECU can directly measure, as follows:
l Sensor hardware faults
l Valve hardware faults
l Sensor and actuator supply faults l Bus failures
l ECU hardware errors.
Plausibility checks are checks on signal behaviour, as follows:
l l
l
l l
Average height does not change correctly
l Height changes too slowly
l Suspension moves in the wrong direction.
Reservoir pressure
l Does not increase when reservoir filling requested
l Does not decrease when reservoir used to lift vehicle l Does not decrease when reservoir is vented
l Pressure varies too much when inactive.
Compressor temperature
l Increases when compressor inactive
l Does not increase when compressor active.
'Energy' used to change height of corner
l Too much 'energy' used – height change takes too long or long term filtered height does not reach target.
Sensor activity
l Signal floating
l Inconsistent signal characteristics – signal on one side of axle is varying but other side remains static l Constant articulation when moving.
When a fault is detected, the ECU will attempt to maintain a comfortable ride quality with restricted functionality of the air suspension system.
The system functionality depends on the severity of the fault. The faults are defined as minor or major faults.
Minor faults are:
l Most sensor faults (hardware faults and plausibility faults) l Cross link valve failure
l Reservoir valve failure.
For most minor faults, height changes are inhibited except for a return to standard height. If the suspension is not in standard height, the ECU will respond to a request for manual or automatic height change to return the vehicle to standard height. The ECU will continue to level the vehicle at the 'current' ride height.
Major faults are:
l l
Compressor faults
Plausibility errors – for example:
l Average height does not increase when lifting and the vehicle is moving. This could be caused by a
compressor fault or a fault in the reservoir valve.
l Reservoir pressure decreases when filling requested. This could be caused by a leak in the common gallery
in the valve block or connecting pipe.
For major faults the ECU will not level the vehicle at the 'current' ride height. The ECU freezes height changes until it receives a manual or automatic request for height change. The ECU will return to standard height and freezes once standard height is achieved.
If the air suspension ECU loses information regarding vehicle speed, the ECU cannot determine if the current ride height is suitable for the vehicle speed. The ECU immediately returns to the 'default' height, which is 20 mm below the standard height. Once at the default height, the ECU will continue to level the vehicle at this height. A loss of the speed signal could be due to a fault in the CAN Bus or a fault in the ABS ECU. It is unlikely to be a fault in the air suspension ECU. It may, for example, be caused if the battery is disconnected and the steering sensor is not recalibrated immediately after reconnection. In this case a CAN Bus fault is recorded in the error memory. If this fault is seen, other ECU's using the CAN Bus should be also be checked for faults. When the fault is repaired, the air suspension ECU will resume full functionality but the CAN error remains in the memory.
60-24 DESCRIPTION AND OPERATION
SUSPENSION
If the suspension is above the standard height and the air suspension ECU cannot lower the suspension or cannot determine the vehicle height, all height changes will be frozen. The ECU will issue a message on the CAN Bus which is received by the instrument pack which displays a maximum advisable speed in the message centre of '35MPH'. an immediate 'freeze' of the vehicle height is caused by the following:
l Failure of more than one height sensor
l Implausible articulation symptoms detected
l Valve or solenoid failure (does not include reservoir valve)
l Stuck corner or whole vehicle (diagnosed using plausibility of the sensor inputs).
If the air suspension ECU has a hardware fault, the ECU will disable all air suspension functions. Detectable hardware errors include memory error, ECU failure, calibrations errors.
Fault Messages
The air suspension has two methods which it can use to inform the driver of a fault in the air suspension system; the air suspension control switch LED's and the instrument pack message centre.
When minor faults occur and the air suspension ECU is able to level the vehicle to the 'current' ride height, the control switch LED's will display the current ride height. When the vehicle returns to the standard ride height and further height changes are disabled, the 'HOLD' LED in the control switch will be permanently illuminated.
The air suspension ECU suffers a major failure and there is no air suspension control, all the control switch LED's will remain unlit.
If a fault occurs and the ECU can determine the ride height and the vehicle is not above standard ride height, the driver will be notified via a 'AIR SUSP. INACTIVE' message in the message centre. If the ECU cannot determine the height of the vehicle, or the vehicle is above standard ride height and cannot be lowered, the 'AIR SUSP. INACTIVE' message is accompanied with an alternating 'MAX 35MPH' message.

Hi..no I don`t have a reader but there`s a garage up the road who has one. I`ll pop up on Monday  Steve.

Cymruambyth wrote:

No...all he did was tap the unit with a small hammer and use some electrical spray. He said they can get blocked and a light tap usually sorts it.

Reservoir level is ok....checked that and others earlier after I washed it.

It seemed to solve it.....till now  Steve.

Hi Cymruambyth, not sure if this would help you, seeing as you are in North Wales, and can’t be that far from me, Abergele/ Llandudno area, if you would find it useful you could pay to have your VIN number added to my GAP Diagnostic account, and then you can come across or meet, and be able to use my IID BT tool when required, to read errors, make alterations etc.
If of any help to you, let me know, don’t know what your engineer charges, so depends on that really, but obviously you could use more than once until you get your own. John

RRS MY12 SDV6 HSE. Sumatra Black/Ebony & Walnut + Dynamic Pack, + Cold Climate Pack + Memory Pack, Digital TV/DVD, Premium Leather, Cornering Lights, Cooler/Fridge Box, & most Options.

Ahhhhh thanks Johnski...really appreciate that I`m in Wrexham, so about 45 - 50 miles from you. I`ll see what I get charged tomorrow and then work out supercharged fuel costs  Steve.

No problem the offer is there just in case, once I’m driving fully again, I could always meet half way if required.  John

RRS MY12 SDV6 HSE. Sumatra Black/Ebony & Walnut + Dynamic Pack, + Cold Climate Pack + Memory Pack, Digital TV/DVD, Premium Leather, Cornering Lights, Cooler/Fridge Box, & most Options.

Nice one, cheers matey  Steve.

I`ve been to the garage. He plugged is reader in and there were about 17 faults, old and new. He cleared them all, then I drove round the block and the amber DSC light came on.

He plugged back in and there were 6 live faults. 2 were Dynamic response communication issues, one was a park control communication one (didn`t surprise me as it`ll beep even when I`m nowhere near anything). Another was an ECU to front light module communication issue. Anyway, he said he`ll need it in for 2 days, 1 to diagnose everything and work out a quote for whatever needs fixing and the second day to fix it......sounds like it may be ££££££££  Steve.

Last edited by Cymruambyth on Tue Nov 14 2017 2:13pm. Edited 1 time in total

so the only ones you need to worry about are the 2 dsc comms issues then which could be a loose wire a broken wire or a faulty modual

Yeah exactly. He did say it wasn`t a broken wire though Could just be the filter in the module hopefully. Steve.

If its not a broken wire how does he know for definite