Now I am poking about in the back of these connectors is there a special multimeter clip or probe to make this easy? At the moment I'm just stuffing a bit of bent copper up against the connector's rear but I'm not proud.

 

Well I wired up the front left shock solenoid from the pins in the trunk/boot and it worked perfectly switching between 0v and about 6.4v. Normal country lane driving 6.4v give it some into a bend and 0v, go below 5mph and 0v so although not tested at the shocks I think it's fair to say the ADCM is giving it its best shot.

The Posi-taps haven't arrived yet and I may test at the top of the shocks but I doubt that there's a problem.

It is (as you were probably all thinking) partly my imagination and mostly shot rear shock bushes giving a harsher ride. Sigh.

So, once we get a run of warmer weather in the UK I'll get under there and change the bushes.

If/when the posi-taps turn up I'll probably use them and report again.

 

You getting 6.4v at the module is certainly in line with me getting 5.7v at the shock itself, so I think we can say that is a normal voltage for the system and it sounds like yours is operating correctly.

I'm not sure how much there is to gain now by testing at the shock itself - if you want to test for continuity just unplug the connector at the shock and you will get Suspension Fault on the dashboard if the wiring is ok. Only the front shocks are easy to get to - I don't know if you can reach the connectors on the rears.

The other possibility I suppose is that your CATS shocks themselves are no longer switching properly between soft and hard - the best test for this is to take your car out on a quiet road, and try rocking the steering left/right at 60mph - this should activate the CATS and you should feel the difference when you see that voltage drop to 0v (or in my case, the tell tale LED go out). Either way let us know how you get on.

 

You see you have rather put your finger on my problem. I have tried your rock and roll suggestion and the voltages say the suspension goes hard and when I stop it goes soft. But it always feels harsher than I think it should be (certainly compared to my old XJ6) which is why I'm thinking I'll tackle the rear upper shock bushings. The lower one was in a terrible state so I suspect the uppers are shot as well. So that's my plan to deal with the upper bushes which I find daunting but I'll do it. Then I'll take stock.

 

Are you sure you're comparing apples with apples with the reference to XJ6.
Unless the wheels, tyres and all associated parts are same or similar l don't think you will ever get the "smooth" of the XJ in the XK.

 

I agree it's probably an unfair comparison but the ride is harsh so there's something not right. It will be a bush somewhere and the obvious candidates are the ones rear top given the state of the bottom bush.

 

All I can tell you is that my XKR convertible on 20" wheels is really comfortable. When the CATS wasn't working properly and staying in soft mode, the back would waddle around quite noticeably on roundabouts etc - in other words, soft mode is quite soft.

 

Isn’t the hard mode the default mode if the CAT system is not working ?

Z

 

Jaguar seem to say that it is, and at 0v that makes it an easy default to use.

 

I believe my CATS work perfectly and that I had too much air in the tyres for a soft ride. Yes I'm dim.

However, the story has moved on Still got a squeak

 

I'm fascinated to find out more here... I have a 2002 XKR which as far as I know means it has CATS (it has wires on the tops of the shocks) and I have an iCarsoft i930, but whenever I scan the suspension module it says it can't talk to the module. Dont know if thats a scan tool problem or a CATS problem. No idea what "too soft" or "too firm" feels like, because my other cars are a miata on coilovers and a Toyota Tundra

 

As pointed out previously, the simple way to test the CAT shock setting is to test the voltage at the shock, or somewhere else between the module and the shocks.

I don’t think the issue you describe is with your scan tool. I have the next more recent model of the icarsoft, the icarsoft LR v1. It will not display any information about the hard or soft shock setting. And from what I read on this forum, that is the norm.

Z

PS : yes, you have the CAT shocks if there are wires connecting to the top of the shocks.

 

If you aren't getting the "Suspension Fault" message on your dashboard, your code reader won't find any codes, (even if it could connect to the cats module).

To test that your module is working, unplug one of the shocks under the bonnet and you should get the "Suspension Fault" message on the dashboard - if you don't get the message, the module isn't working or isn't connected to the dashboard. All the shocks will be permanently in hard mode until you plug the shock back in again.

Compare the ride comfort with and without the shock plugged in - you should be able to notice the difference.