For the last 4 years I’ve noticed the active suspension isn’t working. First indication was when switching between dynamic mode there used to be an obvious difference on rough roads. Now it is always rough. The shocks act like they are dead. Going over bumps and small potholes bangs hard where before it was cushiony soft. The handling is now mushy and the car will sway easily when going around curves. I’ve had to slow way down. I can handle better in my Lexus ES350 now. It’s so hard now that going over expansion joints on the highway will kick the cruise control off. The dealer couldn’t/wouldn’t fix it. They said there were no error codes and didn’t see any problem driving it. They checked the solenoids and said they are moving. They never drove it over rough road or tried handling. I went so far as to have new shocks installed. They restored the ride and handling for all of a few days before the ride starting getting hard again. It’s as if the fluid in the shocks is slowly getting pushed out or the valves aren’t working correctly. When the car is left up on a lift for awhile the ride will improve temporarily until it slowly gets hard again over a few days as if the fluid moves back into the shock then gets squeezed out again with the weight of the car on it. The warranty is up now and I can’t enjoy the car like this. Please help with any suggestions. I refuse to give up on this car.

 

CATS is electronically controlled. The first thing to do whenever there's an electrical problem is make sure that your battery is fully charged. Then see if there are any Diagnostic Trouble Codes. The dealer did those steps to no avail.

I suggest that you try a hard reset. That may clear the memory in the CATS modules. It's worth a try. See Brutal's post #6:
https://www.jaguarforums.com/forum/x...eset-ecu-4258/

Also, see this thread:
https://www.jaguarforums.com/forum/x...brated-101217/

 

The 2012 on cars have a different set up to the earlier cars I think- they don't use the CATS dampers from earlier cars from what I recall.
I think a diagnostic scan might be a good starting point, plus an inspection of the suspension on a ramp.

 

A hard reset can't hurt, and might help.

 

My first thought was:
1. worn dampers - but you have replaced them

Second thought:
2. check for relevant codes - but dealer has done that

You wrote that "the new shocks restored the ride and handling for all of a few days before the ride starting getting hard again. It’s as if the fluid in the shocks is slowly getting pushed out or the valves aren’t working correctly. When the car is left up on a lift for awhile the ride will improve temporarily until it slowly gets hard again over a few days as if the fluid moves back into the shock then gets squeezed out again with the weight of the car on it."

I agree this is a very likely explanation - the fluid flow is not being correctly activated. Here's the description from the Workshop Manual:





If the oil flow is inhibited then effectively your Dynamic suspension is ........ Static.

I'm still mystified that the dealer found no codes. The Workshop Manual has the following explanation for a system fault.

When a fault is detected, the ADCM implements a strategy based on the type of fault. If there is an electrical power fault, or the ADCM cannot control the dampers, they default to the firm condition. If a sensor fails that only affects one or more control modes then an intermediate damper setting is used as the lower threshold and the remaining working modes can demand higher damping as required. In the event of a high speed CAN bus fault, the dampers are fixed at an intermediate setting (no control) or default to the firm condition, depending on the severity of the fault.

Graham

 

Thank you for all your input. Seeing the diagram I now understand how this system works. It seems worse than being stuck in hard mode. It is like the shocks are dead. They can’t control the car on handling and it will sway back and forth with brutally hard ride that will bend the wheels on hard bumps. Maybe the codes are only in certain modules. I don’t know how the dealer went about it but they did not want to spend any time on it since it was warranty at the time and they wouldn’t get reimbursed for their time. When they removed the plug from the damper the error light came on the dash and went away when reconnected. They saw the solenoid move but maybe it doesn’t respond properly. They did a reset of the transmission module which fixed shifting delays with the paddle shifters. There were no codes for that either but the reset fixed it. I don’t know if resetting the suspension module could make it start working again. I would need to go to a dealer that has a skilled technician to do this. The dealers by me just blow it off. Do you know a good dealer in the northeast I could use? I’m on Long Island. I’m willing to ship the car anywhere at this point to get it fixed.

 

I just went out in the garage to try pushing down on each corner of the car the to see if there is any rebound. But when I push down nothing happened. I couldn’t push it down even a fraction of an inch it wouldn’t move like it’s completely bottomed out. Again the ride is much harder than it would be in normal dynamic mode.

 

Maybe you ought to give the manufacturer of the shocks a call or email them describing the problem

 

As mentioned above, the shocks default to firm mode when depowered so that probably isn't a good test. I have just checked my 10 XKR and can't really make it move either. Aren't the springs responsible for the ride height anyway?

Do you have access to the Jaguar diagnostic gear because you can monitor the modules and output with that. I have a cheap OBD tool that can display lots of info that generic OBD dongles won't and, as you can see from the attached, it shows whether the shocks are currently set to hard or soft, sensor voltages etc. If you had something like that you could at least tell if the system is trying to work properly.

 

I tried calling Bilstein but they wouldn’t answer any questions. They said if the shocks aren’t defective I have to work with the car manufacturer to fix it. They said I could send the shocks back to them for inspection but I know they are good. I just replaced them.

 

can you give me the name of the OBD tool you are using and where I can get it?

 

It's on the top of the report, Autel HT200. I think the new version may be AP200. They're available on eBay and Amazon. I used one to set my ebrake into service mode when I replaced my rear pads and to also reset my battery management system (BMS) after I replaced it.

 

were the springs replaced? or the spring isolators?