CATS actual function
 

Hi Folks. Can someone please explain to me in simple terms how CATS suspension is supposed to operate and if it is affected by switching on of the S sports button. Mine feels distinctly different in the way it handles poor roads in S mode but other posts I've seen say that S mode has no influence on CATS whatsoever, only on gearbox shift settings. I replaced all 4 adaptive shocks along with all the other usual failed components within the last year so in theory the system should be factory fresh. Thanks in advance, Jeff

There is no relation to the transmission S mode.

There are accelerometers in the car that under certain conditions will set the CATS suspension to “stiff” mode. It only affects the rebound of the shocks, not the compression direction.

It could be that the poor road bouncing about is enough to set the shocks into their stiff mode.

As I understand it, the stiff setting will be selected automatically, a default setting if you will, if there is some fault indicated ?

true ?

Z

Thanks. I was afraid you were going to say that. I've read on other Jag forums that the S mode has no influence on the adaptive suspension but have also read posts from folks with my exact model that state they notice a substantial difference. Are you sure that on the 2003 with the R performance spec that it definitely remains unaffected? From the seat of the pants you'd swear it changes the rebound in S...

Maybe some people get confused because differences in front wheel speed (the car senses that you are in a turn) can activate Sport Mode when selected.
The other way that Sport Mode is activated is under hard acceleration.
But Sport Mode is strictly a transmission function as far as I know.

To test your CATS suspension is working correctly, you can connect a multimeter set to the volts range to the wires leading to the shock. I used posi-tap connectors at the connector on the shock, ran the cable back to the cabin and put the multimeter on the dashboard.
https://cimg0.ibsrv.net/gimg/www.jag...d28725546f.jpgThese are the values you should get:-

Ign off 0v - hard mode

Ign on stationary 0v

Above 5kmh 5.7v (forward or in reverse) - soft mode

The shocks should switch to hard mode (i.e. 0V) if you go over bumps, corner, brake or accelerate. Waggling the wheel left to right at any kind of speed should also switch to hard mode.

As far as I know the Sport switch is not connected to the CATS from the factory, but it wouldn't be difficult to add some wiring to do so - perhaps a previous owner did this.

If you unplug the connector at the shock, you should get a SUSPENSION FAULT message and all shocks will default to hard.

100% sure. I have watched the behavior of the system with the dealer software with S on and off. The sport mode is just for the transmission.

But if you want it to have an effect, that can be done as well with some modification.
https://www.jaguarforums.com/forum/x...-switch-73487/