Any ideas as How to pump-up air suspension system on 2004 xj8 x350 , so that I can test the system for air leaks?

Can I "trick" compressor to start and pump-up the system?
Car shows "low suspension" on dashboard.
Believe car is in "Sleep mode".
Car has been not driven for past 6 months, and has lowered itself to max.
Live in Los Angeles. In past 6 months, I have only moved 2004 Xj8 from one side of street to the other each week. (Street sweeping days)
Never more than 25 mph, so ... i believe that car has remained in "Sleep mode".
If all else fails, can I use a shop compressor and connectors to inflate system?
Yesterday, ran car at idle for 1/2 hr, and I did not hear compressor begin.
Please send me any thoughts or ideas...

my iCarSoft 930i Jaguar multiscanner shows.. in active read while at idle:

LEVELING in Progress: NO
Front Left Height Sensor @ +3.425
Front Right Height Sensor @ -2.913
Rear Left Height Sensor @ -2.756
Rear Right Height Sensor @ -2.638
Exhaust Solenoid: Closed
All Damper Solenoid valve output controls: Closed
Height sensor voltage: 4.90 v
Laterial Accelerator: -0.03
Pressure Sensor: 11.40 Bar
Pressure sensor supply: 5.10 volt
... and a DTC fault scan shows the following...
B1671 battery module voltage too low ... measures 10v
C2303 reservoir plausibilty error ... need air to test for leaks
U1900 CAN bus fault
U2518 CAN error
U2521 CAN error
U2523 CAN error

 

Repeated short term starting and shutting off will drain a battery significantly. Especially over many months. Even though you recently ran the car for 30 minutes there may be an issue with the battery. Check the state of the battery before you next start it or do anything else to it. Then, since it is going to probably be below 12.4 volts, I would try and charge it slowly over night and see if that makes any difference. A low voltage trickle charge can sometimes help out a neglected battery.

Low voltage will cause many issues with these cars and the one reading of the low voltage could reflect this. I recall reading where one member did make an adapter to use a compressor to inflate the suspension so that can be done. The other problem with sitting for long periods of time is that the elements will cause fittings, like those on the air suspension, to begin to leak. I would check the battery and all fuses. Perhaps even removing and replacing them could improve poor contacts even if the actual fuse is not bad. A bad fuse/connection can stop the compressor from engaging. I believe there are some recent posts as to which fuses are for the suspension and where they are located. The handbooks may be of use in sorting out the CAN errors. Good luck.

 

Start the engine and if necessary drive around for up to 20 mins and it should rise.,

 

Actually it is not the Handbook I should have suggested. It is the X350-Workshop US003 - Chassis manual you can download at the top of this forum. There is a ton of diagnostic information on the air suspension there.

 

With the key out of the ignition, raise the vehicle above it's normal ride height. (tires almost about to raise off floor) Place key in ignition, and start. Allow vehicle to run for more than 2 minutes. While the vehicle is still running, slowly begin to lower the vehicle until it is just under normal ride height, and the pump should start and begin to attempt to level to normal ride height.

 

I posted an answer to your private message.



I have both WDS and IDS so I just go into the Setup and Configuration tab, Air Suspension Module and choose RAISE VEHICLE.


I don't know how a supply of compressed air cab introduced into the system. The system pressure is higher than most shop-air pressures but 120 to 150 PSI will raise the car some.


You can 'jump' the compressor relay (pins 30/87 or 3/5 whatever markings on the relay). Relay R1 in the Front Power Distribution Box is the relay to 'JUMP' to energize the compressor.



I have replaced many relays with 'burnt' contacts and always replaced the relay when I replaced a compressor.


bob

 

Battery voltage should be corrected as others have stated.

My personal method when i had a fault and needed to raise the car to find the fault was to add power to the compressor fuse.

Ive added a picture of the fuse box to " my album" ( no idea how to resize it yet) fuse 6 with the purple nail varnish dab.

Adding power to this fuse (thru a fused wire in case of a fault) will power up the compressor directly without special diagnostic equipment.

Hope that helps along with the above suggestions.

 

Thanks to all..
Special thanks to expertise of .... Bob/ motorcarman... Box... and Tidla..
you fellas clearly understand my issue... need to air-up system to begin mechanical air-leak detection, and determination of compressor capability. .. At this juncture, electrical is secondary issue & less important.. regards, bradley

 

Adding power to 40 amp fuse F6 is the SAME as 'jumping' the 30/87 relay (R1 in the front power fuse/relay box) slots.
The relay provides power to the 40 amp fuse and that will run the compressor direct.


Even if the compressor runs, there are valves to distribute the air that may or may not function correctly??


bob

 

Thanks Bob,..
your info is what I anticipated..
"tricking" computer out of "sleep mode" to begin compressor filling of reserve tank is my goal...(while air suspension is completely deflated and without my being able to drive my X350 on highway or street).
By "tricking" computer to fill air system, then I would be able to determine where air leak is.
I suspect air leak in Left front air line or strut, and probably weak compressor.

 

Jumping the relay to energise the compressor won't help (indeed it may damage the compressor) because both the compressor valve and the reservoir valve in the valve block need to be open when the compressor runs.