I am still getting the plausibility error. Looks like the compressor may be a bit weak. It never ends. Coilovers are looking better.

Eddie 04 VDP

 

The compressor is the shortest life component in the whole air system, so if you have had to do the rear shocks, this was obviously already on the way out. Not a too expensive part, but believe me, I know what it's like when you get that "Black Hole" (for money) feeling. If you go to steel, you will lose the variable shocks and other electronic stability tricks Jaguar have built into the system, (at least that is my understanding).

 

I have decided to go with the new compressor. The current one won't pump up above 175 to 180 PSI. If that doesn't fix it then it is coilovers. If I sell the parts I remove I will about break even.

Eddie 04 VDP

 

Eddie, I see ARNOTT has their brand compressor available on ebay for $399, while oemonlineparts.com sells the Jaguar compressor for $612 w/core of $84. There are a few other new and used oem compressors on ebay. Have you sourced a new compressor yet?
Bob

 

I bought an allegedley new one on Ebay. I am confident now that I have replaced the leaky bag that the new comp will do the trick. The old one will not pump up above 180 psi which will trigger the plausibility error as I understand it. I installed a gauge in the tank. It is a good tool. The car also appears to have leveled itself. Maybe the end is near.

Eddie 04 VDP

 

Eddie,

Do you still have your old compressor?

I need some compressor parts to progress making new seals.

Shipping whole compressor is prohibitive,it weighs 8Kg.

If you can remove piston, seal and aluminium cylinder and ship to me, I will

purchase parts and pay shipping to Australia.

Bob

 

Bob

Sent you a PM. There certainly should be a market for them.

 

Good News: Car appears to be fixed

Bad News: Has two DTCs I can't clear. They show up in Auto Engenuity as Permanent codes.

To recap

Had a leaky left rear shock which I replaced. also replaced weak compressor. Old one wouldn't pump up above 180 PSI. New one goes to 200+ quickly.

I have the batt disconnected to see if that will clear the codes. If not hopefully they will clear in time.

Bob, PM me with instructions about the return of your scanner.

Many thanks to all who helped.


Eddie 04 VDP

 

As we say in the pilot business, I am out of airspeed and ideas. The car still shows two faults that won't clear.

C1830-Air Suspension Compressor Circuit Failure

I may have caused this fault when I was jumping the relay while troubleshooting. But there is nothing wrong with the relay or the circuit. I took the back seat out today to access the ASM. I thoroughly checked that circuit and can find nothing wrong with it. The compressor runs when i apply 12V to the relay trigger.

C2779-Air Spring Solenoid Failure

Same thing with this one. They show in Auto Enginuity as permanent faults. All the solenoids work fine.


Since I can't clear them the car thinks it is broken and refuses to level itself. I can do it manually but it won't level automatically and the "Air Suspension Fault" stays on.

I now have it sitting overnight with the battery disconnected.

 

Eddie, I suspect the controller senses the relay was shorted to +12V during your test. The table below suggest a pinpoint test for each of the DTC, but I can't find a description of Pinpoint test X & Q. Is it possible that one condition is causing the other and if so, which is the primary? When you applied 12V to the relay for powering the compressor, did you disconnect the wire from the ASM? Have you measured the voltage coming from the ASM to the relay during a start cycle? That's CR91-12 ( Brown & Red wire) from ASM. Maybe the ASM needs to be reprogrammed to clear a persistent C1830 "short to B+" condition sensed by the ASM when you applied 12V to the replay.

If you swap out the ASM with replacement module, does it have to be reprogrammed or flashed to match the vehicle. Is there a chance the ASM is somehow stuck in transportation mode and somehow causing these codes? I'm curious if following a procedure to cycle the vehicle out of transportation mode would clear these codes. I don't know if there is a procedure to do this without using a Jaguar specific IDS. Another consideration is the AE diag tool is reporting an incorrect DTC. That happened with me when diagnosing an OPS problem. You may considering finding an independent Britsh car service shop that has an AutoLogic diag tool and have them pull the codes to substantiate what the AE tool is reporting.
Bob
C2779Air spring solenoid supply/drive circuit malfunction

• Air spring solenoid supply circuit; short to ground, short to B+
• Left-hand front air spring solenoid drive circuit; open circuit, short to ground, short to B+
• Right-hand front air spring solenoid drive circuit; open circuit, short to ground, short to B+
• Left-hand rear air spring solenoid drive circuit; open circuit, short to ground, short to B+
• Right-hand rear air spring solenoid drive circuit; open circuit, short to ground, short to B+

For air spring solenoid supply/drive circuit tests,GO to Pinpoint Test X

C1830Air suspension compressor relay circuit malfunction

• Compressor relay drive circuit; open circuit, short to ground, short to B+

For suspension relay drive circuit tests,GO to Pinpoint Test Q.

 

yep Eddie you did set these when jumping the relay and disconnection of the shock connector. This will happen wether key is on/off. I dont think youll be able to reset this with abttery disc since I dont believe its in volatile memory...but Ive been wrong one time before

 

So do I have to take it to the dealer or what?

Bob, I tried in the other forum and found nothing usefull.

 

I did it both ways. I can work everything manually.




No

That's what I am afraid of.



Yes to program the height sensors.


It shows in operational mode.

The circuits from the ASM to the various sensors and components are all just direct wires. I disconnected the plug from the ASM and check them all for short to ground and voltage.

At this point I will have 3 options

1. Find someone with a better computer

2. Install an aftermarket controller

3. Swap the whole mess out for Coils.

 

Well I have made up my mind. I have been struggling with this problem for almost a month. I am going to order the coilover conversion from Arnott. One less idiot light to worry about.

I will soon have all the components of the air suspension for sale. With the money they bring I should just about break even.

 

Eddie, You'll still need to have the ASM reset to clear the permanent codes and clear the light after installing the steel spring and resistor loads, so why not do it now - before buying the steel springs. The permanent codes and warning light won't go away until you do that.. steel springs or not. The ASM has a CAN bus for communicating status and the stored conditions must be cleared. You've completed all the work for the air spring/compressor R&R and so now all that is necessary is for the ASM to be reset and ride height established/calibrated. You are 98% complete and you may have an easier time selling components from a working system. Once the ASM is reset and all lights and codes silenced with your current setup, the steel springs replacement can be done in pairs without having to revisit the indie shop or dealer for ASM service.
Bob

PS. Another consideration is to pick a used ASM and swap it out with yours...assuming the ASM came from a wrecked vehicle, it shouldn't have any permanent codes present and ride height should be set. I read in another thread where a shop replaced the ASM and from reading between the lines... it did not appear that the ASM needed resting or calibrating... You should be able to find a used ASM for around $50 or $60. I've picked up used RCM's and OPS modules from a guy in Plano on ebay for around that price. He has several 04's being parted out.
Bob

 

Thanks for your thoughts Bob.

I have thought about this long and hard.

If I do the coil conversion it tells you to completely unplug the ASM. Just for grins, I tried that. If you unplug and remove the two fuses, the car does not know it is there and is fat dumb and happy. No warnings or faults.

I thought about taking it to the dealer and seeing what they can do but to tell the truth, I would still be riding on 4 used air springs that could go at any time.

I also priced used ASMs. They go for about $250 to $300. Plus I don't know for sure where the codes are stored. I can sell the used air springs for about $250 each if they are pressure tested. That is what Brutal gets for them. The compressor is new and worth about $350. The solenoid block and tank worth about $200. The ASM worth about $250. That is in the neighborhood of $1500 and I never have to see another "Air Suspension Fault" again.


In my opinion the liabilities of the air suspension outweigh the advantages.

Thanks to all who have tried to help. I now know more about Jag air suspensions than I ever wanted to know. Just ask me something!


JMHO. Your mileage may vary. All sales are final. Caveat Emptor.

 

I found an auto electric shop here in West Palm Beach that has factory software and comes well recommended. Their prices are lower than the dealer also. I will take it to them and give the system one last chance.

Eddie

 

Well I went out this morning to take the car to be diagnosed and the front end is on the ground with the "vehicle too low" message. That is the last straw for the air suspension. I will order the coilovers today. I have had it with this system.

Will have components for sale soon. New compressor pumps quickly to 15+ Bar.

 

AAAAAAAAAAAARGHHHHH!!! I have a few last minute questions for Arnott before I order. Unfortunately I have been calling every number I can find for over an hour and nobody answers. Guess they all took the day off. Anyone know the owners cell phone number. Hell of a way to run a railroad. It is 2:50 PM.

 

Finally got a call from them after I sent an email. Order is made. Wish me luck.