If I install my new 2 front Arnott Air shocks, would they bypass the CATS System Fault after installation ?

I need to get rid of the CATS system fault message is annoying to see it all the time specially if the vehicle is running smoothly but I know my front shocks need replacement because in winter the car seats low in the front, in the rear is fine. I got the rear shocks replaced with Arnotts 2 years ago .

 

Call up Arnott or reach out to DougArnott on here. They are very helpful and knowledgeable.

 

Thank you for the question. Yes the Arnott New Jag Struts should turn off the fault codes.
https://www.arnottindustries.com/par...20_pid136.html

 

Can you explain how they do that please?

 

Thanks for the good info

 

I installed the Arnott replacement shocks on my 2004 XJR and they are exact replacements and do plug into the existing CATS system. no errors and the car rides and performs well. These are quality replacement parts.

RyeJag

 

I presume you lose the self leveling feature of CATS?

If that is true exactly what function do the Arnott air bags perform?

Why choose the airbag unit over the coilover conversion?

 

I also replaced one of the front air shocks on my wife's 2004 XJ8 about 2 1/2 years ago with an Arnott remanufactured unit which they were still offering back then. It looked no different in any external way from the new units they are currently offering. It hooked into the CATS system without any trouble and I only replaced it and the rest of the system when about a year later I lost one of the rear shocks and realized I was going to be chasing this problem forever. I then went to a set of coil overs and had to disable the CATS error messages by disabling the module behind the rear seat.

In looking at the pictures of the Arnott shocks on the link supplied the air inlet for the airlines is clearly visible and the factory system does not, as far as I know, have any sensor or module installed directly within the shock and that all signals for any increase or decrease in air pressure are generated externally by the ride height sensors, the external compressor, the reservoir tank in the trunk, and the CATS module itself.


Defeating the CATS system while still having air shocks at all 4 corners seems to me to be a bad deal as how would ride height or shock air pressure be controlled without it?

 

Quote RDMinor "Defeating the CATS system while still having air shocks at all 4 corners seems to me to be a bad deal as how would ride height or shock air pressure be controlled without it?"

Thats why I am asking about the Arnott airbag usefulness/functionality compared to the coil over version..

 

jackra_1, I think that we're misreading what Doug Arnott is saying. Perhaps you can 'defeat' the CATS system as I did when I converted to coil overs to end the constant error codes the module would post but the Arnott air shocks are fully compatible with the CATS and are controlled by it. Several of us over the past few years have installed their air shocks and no one has yet stated that they DID NOT work with the CATS.

You appear to be also asking what advantages, if any, the Arnott shocks have over coil overs. Their air shocks keep your Jag as it was built at the factory and there is a certain difference in the ride quality on poorly maintained roads like you find in areas with real winter weather that causes so much damage to roads. On super slabs and well maintained primary roads I honestly couldn't tell any difference between them and the coil overs I installed and I've been a 'lead foot' for decades.

The single biggest advantage that coil overs have is the substantial savings in money and aggravation you achieve by not having to play Mr. Fixit every time one of the CATS systems components goes haywire as THEY WILL eventually as these cars age. If you have a relatively young Jag, say 5-7 years old with less than 60,000 miles on it you may be O.K. for some time. However, once the CATS system starts to give you trouble it becomes a real headache and money eater that most of us who enjoy the older cars can't afford.

Consider the Arnott's, which are certainly less expensive than anything a Jag dealer would charge you. Even they would run you some $2200 plus labor to do all 4 corners and you still have to deal with failing ride height sensors, failing compressors, etc. Meanwhile a set of coil overs will run you about $1200-1300 plus labor and you'll never have to worry about any of those other components again. In fact you might be able to sell them on eBay and recoup some of the expense of the coil overs.

If you are mechanically inclined you may enjoy the work but as other members have experienced these things don't always fail near your work shop and are just as likely to happen 500 miles away from home or late at night with your wife driving the car.

That said there are purists on the forum who would never convert to coil overs since that, in their mind, reduces the re-sale value of their cars. Personally I don't think my wife's 2004 XJ8 will ever be worth more than I paid for it unless money ends up having essentially no value at all and it takes a wheelbarrow of the stuff to buy a loaf of bread.

 

He does not say that their shocks turn off the CATS.

What he wrote was that their shocks should turn off the error codes.


In other words, if your fault code is for a blown or leaking shock and you replace it with one of theirs the code should stay away once you clear it.

 

CATS is compromised by the Arnott airbag system period.

The self leveling capability of CATS etc is totally eliminated period. That includes stiffening of the suspension under spirited driving to try and keep
the car closer to level in cornering and braking.

Thats is actually fine if you are not worried at all by this fact.

The Arnott system causes the CATS system to "think" everything is fine. When the "transistor like" fix in the Arnott struts fails
you get an error code even tho the airbag is fine.

I am NOT saying the Arnott system is "no good" for what it is.

Tell me I am wrong with some factual information....please.

 

Sorry for any confusion. Arnott designed new struts include auto leveling of the air spring (air suspension) but not the active damping included in Jaguar's CATS (Computer Active Technology Suspension).

Arnott did offer remanufactured Original Equipment struts but stopped remanufacturing them. The often hard-to-find remanufactured struts were tested, cleaned and then repainted before we rebuilt them with a new air spring, seals, heavy duty crimping rings and more. While we did test the remanufactured shocks - and backed them with a limited lifetime warranty - we still didn't know the actual number of miles on the shock, bushings and mounts - or the quality of those miles. As you can imagine this leads to a higher failure rate than we would like so we also began to offer the option of an Arnott designed new strut with zero miles.

Learning from the countless cores that we have rebuilt over the years, the new struts incorporate a brand new custom valved shock but as noted they don't include the auto damping. These shocks have been engineered to provide an O.E. like ride (We offer both Comfort and Sport) and are rigorously tested on our own vehicles. The overwhelming opinion of our customers is that the ride is excellent - but of course they are often replacing worn out original shocks. We assemble the struts here in our Florida facility with new ContiTech air springs which work with the vehicle's auto leveling functionality along with improved seals, crimp rings, top and bottom mounts, bump stops and a bypass resister which plugs into the CATS systems and turns off any dashboard warning lights that the CATS system may throw.

While we always recommend replacing struts in pairs (like any non-air auto shock or strut manufacturer would) we have had plenty of customers install a new strut on one side while the CATS strut is still on the other. Another benefit for the installer and customer is that Arnott's new struts do not require an upfront core deposit or the associated storage and return of the core. Of course they are backed by a Limited Lifetime Warranty and come with a 30-Day Money Back Guarantee if not completely satisfied.

 

Thank you arnottdoug for that excellent clarification.