I have just bought a 2006 XJ tdvi and have found that the ride is hard, think 5 series sport on run flats hard.

It was bought because i needed a car with a smooth ride and i thought with the air suspension this would provide it but around town and on the motorway it feels like the tyres are pumped up to 50psi feeling every bump in the road.

It has had the air pump changed and sits at the right height and is showing no faults at all, but i have heard that the cats suspension can revert to a default safe permanent hard setting until all the previous faults have been cleared.

Can this be done with a Launch Creader VI diagnostic tool or will it have to be done with Jaguar IDS software, it is a 80 mile trip to go to a main dealer to get the reset done so it would be easier to get it done locally for me as it is really putting me off the car.

What tyre pressure & which tyres (make etc)?

It has new 255/40/19 Pirelli P Zero rossos and 28psi front & 31psi rear pressures.

Many people have found the P Zeros very hard and also noisy.

You will need the IDS to clear all the codes, the Creader will not read Jaguar specific codes. I currently have 3 scanners and none will clear the Chassis codes. I had to purchase the JLR Mongoose setup and a Toughbook, I will be installing the software this weekend.

You are on the right track.

From what I have read on this and the UK forum a Cats code can change the setting to hard and has

to be cleared to change back to comfort.

On a Jag air suspension diagram it shows a solenoid for each wheel and for a long time I could not

understand what part this played in the air suspension until I found the answer which is NONE!

The solenoids switch the shock absorber which is inside the air 'bag' and are activated by the two

little wires to the top of each strut.

I have also read that the solenoid just 5 volts' which is probably correct since the wires are very thin

so if you disconnect a plug to the strut will the solenoid switch and the shocker revert to Comfort?

I am thinking of a temporary fix.

I am guessing that the solenoid is just 5v on or off.

From what i understand is they default to hard if unplugged so i might try it to see if there is any difference to how it is just now, it looks like i will have to make a trip to the nearest dealer to get the codes read and reset.

You are correct as I have just discovered.

Comfort setting is 5 volt to the solenoid, so a 5 volt battery connected to every

strut with the plugs disconnected will change the ride to Comfort.


How is that for a temp fix?!

Except that it will throw up a 'CATS Fault' message, I think.