Air Suspension Fault
#21
Hi Don, thanks for the message. I never got a "too low" message. I get the fault after like 20-30 mins after I start driving. Then everything becomes stiff. Weird thing, is that if you don't get the code scanned when the error appears, then after a restart there are NO fault codes in the ecu. I have this WIFI OBD thing I use. I will take it to the dealer today and see what they can find, I will tell them to look for leaks as you described, I hope they find it. But if it is one of the shocks, then I know how much it is going to be
im not sure of a leak just yet but maybe electrical - 1st guess,
Don, whats the unit on the jag's shocks used to stiffen them, maybe something to do with this
get the fault codes 1st
regards
Andy
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Don B (03-03-2015)
#22
Hi Don, thanks for the message. I never got a "too low" message. I get the fault after like 20-30 mins after I start driving. Then everything becomes stiff. Weird thing, is that if you don't get the code scanned when the error appears, then after a restart there are NO fault codes in the ecu. I have this WIFI OBD thing I use. I will take it to the dealer today and see what they can find, I will tell them to look for leaks as you described, I hope they find it. But if it is one of the shocks, then I know how much it is going to be
Hi XJRLondon2004,
As Andy mentions, it does sound as though you may be having a problem with ECATS, which is the newer "Adaptive Damping" system. It is Jaguar's adaptation of the ECAS system by Wabco, the OEM that supplies most of the air suspension to Jaguar (everything but the air springs/dampers themselves, which are made by Bilstein).
The way ECATS works is to modulate the damping rate of each shock depending on driving conditions. The default mode of the shocks, with no electric signal applied, is "Firm." To soften the ride, the Air Suspension Control Module (ASM) sends a pulsed electrical signal to the CATS solenoid in the top of each shock, which modulates the valving to change the damping characteristic to "Soft."
Cambo351 shows the 5V 400Hz 1ms pulse-width signal on a scope in this post:
https://www.jaguarforums.com/forum/x...76/#post544336
Regarding Diagnostic Trouble Codes (DTCs), your bluetooth code scanner can probably only read "P" or "Powertrain" codes (and possibly not all of those). The suspension codes are mostly "C" or "Chassis" codes, and to read them (along with the "B" or "Body" codes and "U" or "Undefined" codes (mostly Network-related codes)), you need a scanner that can read Jaguar proprietary codes, such as the dealer-level Jaguar Land Rover Symptom-Driven Diagnostics (JLR SDD), AutoEnginuity with the add-on Jaguar module, or another high-end system. It is likely that you have suspension-related DTCs logged but your scanner cannot read them.
Please let us know what the dealer finds.
Cheers,
Don
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AD2014 (03-03-2015)
#23
in this case of no faults i would recommend a dealer scan in case the hand held is not reading all faults, this is common.
im not sure of a leak just yet but maybe electrical - 1st guess,
Don, whats the unit on the jag's shocks used to stiffen them, maybe something to do with this
get the fault codes 1st
regards
Andy
im not sure of a leak just yet but maybe electrical - 1st guess,
Don, whats the unit on the jag's shocks used to stiffen them, maybe something to do with this
get the fault codes 1st
regards
Andy
#24
Hi XJRLondon2004,
As Andy mentions, it does sound as though you may be having a problem with ECATS, which is the newer "Adaptive Damping" system. It is Jaguar's adaptation of the ECAS system by Wabco, the OEM that supplies most of the air suspension to Jaguar (everything but the air springs/dampers themselves, which are made by Bilstein).
The way ECATS works is to modulate the damping rate of each shock depending on driving conditions. The default mode of the shocks, with no electric signal applied, is "Firm." To soften the ride, the Air Suspension Control Module (ASM) sends a pulsed electrical signal to the CATS solenoid in the top of each shock, which modulates the valving to change the damping characteristic to "Soft."
Cambo351 shows the 5V 400Hz 1ms pulse-width signal on a scope in this post:
https://www.jaguarforums.com/forum/x...76/#post544336
Regarding Diagnostic Trouble Codes (DTCs), your bluetooth code scanner can probably only read "P" or "Powertrain" codes (and possibly not all of those). The suspension codes are mostly "C" or "Chassis" codes, and to read them (along with the "B" or "Body" codes and "U" or "Undefined" codes (mostly Network-related codes)), you need a scanner that can read Jaguar proprietary codes, such as the dealer-level Jaguar Land Rover Symptom-Driven Diagnostics (JLR SDD), AutoEnginuity with the add-on Jaguar module, or another high-end system. It is likely that you have suspension-related DTCs logged but your scanner cannot read them.
Please let us know what the dealer finds.
Cheers,
Don
As Andy mentions, it does sound as though you may be having a problem with ECATS, which is the newer "Adaptive Damping" system. It is Jaguar's adaptation of the ECAS system by Wabco, the OEM that supplies most of the air suspension to Jaguar (everything but the air springs/dampers themselves, which are made by Bilstein).
The way ECATS works is to modulate the damping rate of each shock depending on driving conditions. The default mode of the shocks, with no electric signal applied, is "Firm." To soften the ride, the Air Suspension Control Module (ASM) sends a pulsed electrical signal to the CATS solenoid in the top of each shock, which modulates the valving to change the damping characteristic to "Soft."
Cambo351 shows the 5V 400Hz 1ms pulse-width signal on a scope in this post:
https://www.jaguarforums.com/forum/x...76/#post544336
Regarding Diagnostic Trouble Codes (DTCs), your bluetooth code scanner can probably only read "P" or "Powertrain" codes (and possibly not all of those). The suspension codes are mostly "C" or "Chassis" codes, and to read them (along with the "B" or "Body" codes and "U" or "Undefined" codes (mostly Network-related codes)), you need a scanner that can read Jaguar proprietary codes, such as the dealer-level Jaguar Land Rover Symptom-Driven Diagnostics (JLR SDD), AutoEnginuity with the add-on Jaguar module, or another high-end system. It is likely that you have suspension-related DTCs logged but your scanner cannot read them.
Please let us know what the dealer finds.
Cheers,
Don
Lets see what they find out,
Many thanks for your comments
#25
Hi, thanks so much for the comments, ok so the Jag is at the dealer, I am waiting to hear from them and will let you know. They told me that they will use special powder to check if there are any air leaks, and also they will check some other issues. I hope they do find the problem....
If the car does not sink down at any time or does not give the "too low" error then their are no leaks, the fault codes will check the operation of the electrical system and let you know if their is a faulty or problem areas or components
regards
Andy
#26
Mine is throwing codes constantly for the active damper circuits. It will set codes for all four corners at seemingly random times. Sometimes it claims there is a short to ground and other times there is a short to voltage (circuit high, circuit low, etc.) Very frustrating... not even sure where to start with the diagnostic process. I suppose I'll back probe all four dampers and use the scope to watch the signal as I wiggle harnesses. I'm guessing something is chaffed.
#27
I have installed two new Arnott front air shocks and the Bagpipe Andy compressor r&r kit. Still getting air suspension fault after 7-10 minutes of driving. Rear shocks seem fine with no sagging at any corner. Could relay be the issue? Also, where is the best place to get relays in the US? I have checked many online sites but cannot find the brown 40 amp one for air compressor. Thanks!
#29
I have installed two new Arnott front air shocks and the Bagpipe Andy compressor r&r kit. Still getting air suspension fault after 7-10 minutes of driving. Rear shocks seem fine with no sagging at any corner. Could relay be the issue? Also, where is the best place to get relays in the US? I have checked many online sites but cannot find the brown 40 amp one for air compressor. Thanks!
Best regards
Andy
#30
If this puff of air is when the compressor stops running this is fine, it is releasing pressure from the airline.
if the puff of air is after you park and lock the car this too is normal and it is just adjusting to either being not perfectly level or weight being removed or added to the car.
if it sinks to the bump stops with this puff of air that is not normal, but I guess it is not sinking down it is just making minor adjustments releasing a little air.
Regards
Andy
#32
#33
Hi , ok so they called yesterday, the did a 24h test, and it turned out to be the right side SHOCK that is leaking a bit of air, so I am assuming there must be some kind of a seal. But they quoted 1100 pounds for the job and I said no thanks. Because it doesn't happen often, and I don't think it makes sense to change just one. It is as if once you start changing things in the suspension syste, as I did with the air compressor, then it is on to the next WEAK spot somewhere. And so on, and so on The only thing I don't understand, is I never got the TOO LOW message, and why the air suspension fault comes on when driving , can it really be because of a leaking shock?
Last edited by Don B; 03-06-2015 at 09:56 AM.
#34
Hi , ok so they called yesterday, the did a 24h test, and it turned out to be the right side SHOCK that is leaking a bit of air, so I am assuming there must be some kind of a seal. But they quoted 1100 pounds for the job and I said no thanks. Because it doesn't happen often, and I don't think it makes sense to change just one. It is as if once you start changing things in the suspension syste, as I did with the air compressor, then it is on to the next WEAK spot somewhere. And so on, and so on The only thing I don't understand, is I never got the TOO LOW message, and why the air suspension fault comes on when driving , can it really be because of a leaking shock?
#35
The thinking is that the sooner a leak or fault is found, the fewer the components that will need to be replaced. Ignore a leak, the compressor eventually pays the price.
When I had a leak in a front shock, it only leaked on very cold mornings, and only very slightly, if I drove it when it was that cold it would trigger a fault. If I drove it on a warm day, it would never trigger a fault. Cold temps expose the leak, and in the short run warm temps will "cure" it, but it will only get worse over time.
Fortunately, replacements or refurbed units are now a lot less spendy.
#36
When I look at the cutaway diagram of the Bilstein air spring in the Technical Notes, it is obvious there is a large complex moulded rubber seal at the top as part of the top mount. We know the air pressure in these air springs is quite high in normal running, and gets verry high when cars get onto full bump, like about 20 Bar odd, which is nearly 300 psi. Also the US gets much colder winters than we do here in the UK.
I'm thinking that in the very cold conditions, this rubber moulding shrinks slightly, but also will get hard and unable to mould itself to the securing steel housing when air pressure gets up against it. So air will be able to leak out and cause all the awful symptoms currently being experienced.
I'm thinking that in the very cold conditions, this rubber moulding shrinks slightly, but also will get hard and unable to mould itself to the securing steel housing when air pressure gets up against it. So air will be able to leak out and cause all the awful symptoms currently being experienced.
#37
When I look at the cutaway diagram of the Bilstein air spring in the Technical Notes, it is obvious there is a large complex moulded rubber seal at the top as part of the top mount. We know the air pressure in these air springs is quite high in normal running, and gets verry high when cars get onto full bump, like about 20 Bar odd, which is nearly 300 psi. Also the US gets much colder winters than we do here in the UK.
I'm thinking that in the very cold conditions, this rubber moulding shrinks slightly, but also will get hard and unable to mould itself to the securing steel housing when air pressure gets up against it. So air will be able to leak out and cause all the awful symptoms currently being experienced.
I'm thinking that in the very cold conditions, this rubber moulding shrinks slightly, but also will get hard and unable to mould itself to the securing steel housing when air pressure gets up against it. So air will be able to leak out and cause all the awful symptoms currently being experienced.
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