I have a 2003 xj8 air shocks are good how do I check to see if pump is getting power , it will not throw a code ?

 

Welcome to the forum.
(1) Technically they are not air shocks, but air springs with dampers.
(2) You are posting in the wrong forum section. This is the X308 and you have an X350.

The electrical guide is available for download somewhere in the large file area to locate faults and troubleshoot.

The compressor relays have been known to have 'burnt' contacts and limit the power to the compressor motor.

When I replace a compressor I usually replace the relay also.
It will probably 'throw a code' but unless you can read (C) CHASSIS DTCs you will likely not know what code it is.

The suspension will not trigger 'P' (powertrain) codes.

bob gauff

 

Hi brushpopper,

Welcome to the Jaguar Forums. I have moved your post from the forum for the X308 to the forum for the X350, under the assumption that you are inquiring about your 2004 XJ8 with air suspension as noted in your signature and not a 2003 XJ8 as mentioned in your post. It will help us if you can confirm the model year of your car.

It will also help us if you tell us the symptoms you are trying to diagnose in case we can help shortcut your troubleshooting.

Regarding the air compressor, it is mounted behind the front bumper cover to the left of the radiator, as viewed from the driver's seat. To access the compressor you just have to remove the radiator splash shield on the underside of the bumper cover.

You can listen for the compressor to run beginning shortly after the engine is started, ideally after the car has been sitting all night. At startup, the Air Suspension Control Module (ASM) uses the pressure stored in the air reservoir tank to recharge the system, so the compressor does not always run. If the pressure in the reservoir is insufficient for the car to reach proper ride height, the compressor will run for up to 2 minutes. When it runs, you will be able to hear it if you are kneeling near the front left wheel.

The power for the compressor comes from the Air Suspension Relay, which is Relay 1 (R1) in the Front Power Distribution Fuse Box in the front right corner of the engine bay. That relay has failed on some members' cars, though I'm not sure we're ready to say it's a common problem. The power from the relay to the compressor is protected via the 40A Fuse 6 (F6). 12V battery power should be present at the socket for terminal 3 of the relay, and if you jump across the sockets for pins 3 and 5 the air compressor should run (don't let it run for more than two minutes to prevent overheating of the piston ring and cylinder).

A very common issue is the piston ring seal in the air compressor, which becomes worn over time and the compressor can no longer pressurize the system as quickly as it did when new. Our forum member bagpipingandy offers an affordable repair kit that is relatively easy to install and that's usually all you need to restore the compressor to near-new performance (bagpipingandy.com). If you need to replace your piston ring we'll be happy to provide photos.

You can download the 2004 X350 Electrical Guide at this link:

http://www.jagrepair.com/images/Elec...al%20Guide.pdf


You can download the X350 Workshop Manual in six sections from the X350 'HOW TO' quick links thread on the main page of this X350 forum.

Please confirm your model year and let us know the symptoms you're experiencing and perhaps we'll be able to offer some more specific input.

Cheers,

Don

 

If the compressor isn't working, the car will eventually settle and the dash displays a red light and "suspension low" message. It doesn't mean that the fault is necessarily the compressor, but a bad compressor will cause it.

 

Don, has anyone ever figured a way to re-pressurize the system by adding a Schrader valve somewhere ahead of or into the reserve tank for those instances when your pump gets weak or goes bad?

It would seem to be a relatively easy job to get a person with aluminum welding skills to add one to the reserve tank so you could refill it manually if needed.

 

Hi RDMinor,

That idea has been tossed around but I don't recall hearing from anyone who's actually installed a Schrader valve. I would think the easiest place to install it might be in the air hose between the valve block and air reservoir, if you could find the necessary fittings.

Since replacing the compressor piston ring is such an easy job, it may not be worth the effort to install a Schrader valve for repressurizing the system, but there are times when it might be informative to connect a pressure gauge. lcmjaguar fabricated some test gauge hookups that he loans out to members who need to test their suspensions:

https://www.jaguarforums.com/forum/x...s-loan-126934/


Cheers,

Don

 

the previous owner of my XJ8 had his mechanic install tire stems on the front struts and pumped them to 150 psi - of course the mechanic left the air lines "open" causing a C2302 code.

If they would have disconnected those front air lines at the block and capped each off - this would have worked.

And the kicker was one of the struts was a new Arnott strut.

I reconnected both air lines w/ new nuts and olives and works 100% (except for minor leaks at the adapter below the air line nut (which shouldn't have been removed)

I am actually modifying a set of 90 degree long needle nose pliers to tighten the fittings.

Hope this helps

 

Very good post, please provide pictures of air compressor pistons I'm having a faulty compressor, the dealer states that it's going bad but still works fine I think it might be the piston ring

 

Rf69, check out this post regarding the air compressor.

https://www.jaguarforums.com/forum/x...ressor-136272/

 

Hi rf69,

Here are links showing how to replace the piston ring seal. I also replaced the desiccant in the air dryer, but most owners don't bother with that. But do clean any corrosion you find inside the compressor (which is a normal byproduct of moisture in the incoming air):

Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page


Cheers,

Don

 

Good info!