I replaced my air ride with the Arnott conversion kit. The Air Suspension Fault light remains on. I disconnected the battery for 12 hours but that did not work. Arnott says that they do not have a fix for the 2008 XJ. Any ideas? Thanks

 

Pull out the CATS fuse and see how it goes.

 

Try placing both ends of the Battery Cables together (Pos and Neg) for a few seconds.

 

"Arnott says that they do not have a fix for the 2008 XJ".

Would that still be a problem on a 2006 ??

 

I've also spoke with Arnott previously and they confirmed that something changed on 2007+ models so the warning light cannot be disabled.

Arnott coil spring conversion kit features list states:
"Instructions To Bypass 04-06 Dashboard Warning Light"

 

Hmmmm.... That's not good news. Has anyone with a 2007+ model done the conversion and managed to solve this problem?

 

So, they sell you a kit, but the warning light stays on............
That's really professional?
In the uk, it would fail the MOT.
I think I'll look elsewhere?


regards.

 

So it appears a 2006 XJ might be the best option for someone in the market for a used X350. The 2006MY had the first round of updates/upgrades and you also have the option to convert the suspension without any warning lights.

 

Does anyone have any idea from which Chassis number / VIN number does this problem start from?

 

According to the Parts manual, it starts from VIN G00442 (mid 2003). There are 5 different part numbers from 2004 to 2009.

 

I believe Arnott stated the issue is with the software/firmware on 2007+ models and not the actual air shock itself.

 

Yes, I'm looking at swopping my XJR for a Jan 2007 registered Daimler and hence my question as I may want to convert to the coilover set (after having so many recurrent problems with the normal air shock set). There's little hope of the car passing inspections if there is a suspension fault message displaying.

 

Try adding a pair of 5K resistors to the plus where the height sensors were
This will emulate the height sensor at aprox 50%
You will need to do this for all 4 removed sensors

This will fool the ECU into thinking the height is OK
You can then go into IDS and fake the ride height.
The info to do this is in Cambo's how to adjust ride height thread

Finally if you have also removed the air compressor you will need to fake the pressure sensor signal

Im not sure of the value so you will need to measure the resistance of the sensor and add a pot in place of the removed sensor. Adjust the pot so you no longer get the low pressure warning

If you need me to go into more detail let me know

Cheers
34by151

 

Thanks. That's good information. Maybe dpriddle can try this solution and let us know.

 

Thanks for the suggestion. I would have to do more research to fully understand your solution since I am not mechanically or electrically engineering inclined.

But I did call Arnott again and emailed your suggestion to them. Their tech support is going to send to their R&D to see if this would work.

In the meantime, I called their competitor, Strutmasters, who said that they provide instructions on how to unplug a black box module located behind the back seat. This would eliminate the "Air Suspension Fault" light but would cause the "Check Air Suspension" light to come on. This light could be shut off by selecting "reset", but it would have to be done each time the car is started.

They were not 100% sure that this solution would work with the 2008.

I will check back with Arnott to see if they have analyzed your suggestion.

Thanks

 

To put it simply you get a suspension faults under 2 conditions

1. Ride height out of limits
2. The air tank does not reach pressure in time (5mins I think)

How the ECU knows the ride height is a sensor on each wheel
If you look at page 05.3 in the electrical diagram you will see the 4 sensors marked as height sensor

The sensor has 3 wires
+5Volts, OVolts and output

All the sensor is is a pot or variable resistor

If you connect + power, ground to each end of a pot the 3rd pin give you a voltage between the two and relative to the the amount the pot is turned
IE all the way one way, output = the + power, all the way to the other end you get ground and it varies in between

So this is all the height sensor does give a voltage between o and +5 relative to the height of the wheel

If one of these signals is low the ecu signals the solenod to add air to the airbag raising the wheel. If the voltage is gigh it purges air. The goal being to achieve the value set in the SDD

If it cant do this you get a suspension height fault

So faking this will prevent the height fault as ithe ecu always thinks you have the correct height

For the Compressor waning, the ecu tries to keep a stable pressue in the tank. The tank is in the boot under the valve block.
The sensor is on the same page labels "Valve Block pressure sensor"

If you look at the page you will see its the same as the height sensor. The only difference is it varys the voltage based on the pressure in the tank

How the ECU reacts is to tun on the compressor when the pressure is low and turn it off when high. How the error is generated is with the pressure low it will run the compressor for 5 mins. If it does not get up to pressure in that time you get the error message.
So giving the ecu the correct voltage fools the ECU into thinking you have a pressurized tank

Hope that helps

If you read this post by cambo351 you will get the idea
The fisrt pic is the height sensor with the plug

Cheers
34by151

 

The 2008 has 3 sensors, the right front was removed/not installed on post Dec 2003 MYs.

 

Dpriddle, just wondering if you managed to solve the problem? Thanks

 

Sorry, not yet. I have been in contact with Arnott who said that they actually purchased a 2008 Jag XJ in order to determine the solution. Yes, I doubted that answer too, but they told me that they just purchased an older Lincoln Towncar and while he was talking to me he was looking at two Land Rovers that they purchased too. I asked what happens with these cars when they are done and he said that they are sold. If this is a lie, it is quite elaborate.
He says that the estimate for a solution is anywhere from a few days to a few weeks. I can wait until then. My biggest concern is passing State inspection, but that does not happen until October and as others have mentioned, if you press the reset button (every time you start the car) then the message goes away. Worst case is that I press it prior to inspection.
It's annoying, but with my limited time and mechanical knowledge, I don't want to attempt solutions that are not proven.
I will keep you posted of any new developments.
In the meantime, I have to take off the inside wheel well of the right front fender in order to fix the leak in the windshield washer reservoir!

 

I think the problem is the vid block in the car is looking for the air suspension. You are have to find a way to reconfigure the car. I ran into a similar situation when trying to add power fold mirrors to a 2008 car. The cars now have the same harnesses but the car is configured to have certain features. This may not be as easy as it sounds to fix. I hope they solve it as the upgrade is a very economical repair.