Fuses re the air suspension system - what do they protect?
I am considering the installation of the FASKIT "external air fill" system. This is an air piping and fill system designed and manufactured in Spain by http://www.opcionesavanzadas.com/faskiting.htm I gather it is common and easy to install on the P38 Range Rover, but not so easy on the Disco 3 / LR3.
While I sort of understand how the kit air lines Tee into the existing LR3 lines, I am not certain about how one goes about shutting down the computer and perhaps LR air compressor, (or it is it necessary)?
I presume shutting down the suspension electronic control system would be necessary as the reason one would activate the FASKIT system is upon full or partial failure of the suspension computer/wiring system. Then once one got the Land Rover system repaired, the FASKIT would just sit there doing nothing until the next time.
With the FASKIT system in operation, it would seem to me that the computer operated Land Rover cross link air valves would have to remain closed so that the air one manually pumps into each corner stays there and is isolated from the other corners. I assume by pulling fuses, that would shut the Land Rover system down, but does that also get the "slow to 50 kph" messages and bells going? Probably not, and I presume the engine still runs etc. but I just wonder what else has to be done.
I think I could run all the air lines forward into the engine compartment and locate the fill connector assembly in the front left empty space near the the windshield washer fill spout. There is empty space there in the gasline engine models - no FB heater - here in Canada, we use electric tea kettle heaters installed in the engine block.
I looked in the owners manual re fuse locations and found:
(A) under the bonnet fuse box, two fuses, Fuse 3, a 5 amp labelled "Air Suspension ECU" and Fuse 26, a 20 amp labelled the same. There is also a 60 amp fusable link labelled FL10 which I presume protects the Air Compressor.
(B) behind the lower glove box in the interior, fuse 35, a 5 amp, again similarily labelled "Air Suspension ECU".
I am wondering what the consequences of pulling one of more of the fuses is?
I presume the air system would be disabled, however would the LR3 then try to go down to the stops or the display would show slow to 50 kph messages or similar. In other words, would I still be able to drive the vehicle? With the FASKIT, I would be able to fill the air springs,(say from an external air source), as required to bring the LR3 to an appropriate height, however would pulling the fuses do anything bad, or would it even be required?2005 LR3 HSE 4.4L AJ-V8 petrol; Traxide Dual Battery; PIAA 2500K Yellow Ion H11 Fog Light bulbs; CounterAct LT-2 Capacitive Corrosion control; LLumar AIR80 Blue clear Infra Red blocking side window film; Liftgate manual release; Schrader Valve "air in" mod to OEM air suspension reservoir tank; Akebono ceramic pads; OEM solid vented discs; LR4 design hitch receiver; Wiggs D4 MOST bluetooth module; Clock on the Dash; 3 Flash signal light mod; Backup Camera; 2015/16 Nav Data update.
19th Feb 2010 6:05 pm
GraemeS
Member Since: 17 Mar 2008
Location: NSW
Posts: 706
The 5A fuse in the passenger compartment fuse box seems to disable the air suspension system without any adverse effect although the speed warning still occurs. It has at least been removed to prevent the system from lowering to the bump stops when the vehicle's wheels were knocked badly out of alignment.
F35 fuse Air Suspension 5 amp behind lower glove box
That is a good news post; that the 5 amp F35 fuse behind the lower glove box seems to keep the computer from dumping the air system completely and hence the vehicle remains operational, sort of.
As far as for the continued fault messages, they really do not matter, (other than the repetitive bonging I suppose), so that is a bit of a relief that one can probably remain off the stops.
I was recently having a suspension wiring problem, (since solved I think - corrosion of some connectors), and for the most part the vehicle was driveable while we were trying to find the problem - except periodically when it would go down to the stops - then it was not just a minor inconvenience.
I appreciated the exhaust system/underside view of the Disco 3 in your gallery. Is there anything similar for the air suspension hose routing? I think I have a pretty good idea where they are routed, but a picture can be a real help.
It seems that the front air suspension valve control is located kind of inside the front bumper behind the fog light on the right side. It appears that both air lines from the front air springs and a supply line from the air tank plus an electrical control cable all meet at that valve setup.2005 LR3 HSE 4.4L AJ-V8 petrol; Traxide Dual Battery; PIAA 2500K Yellow Ion H11 Fog Light bulbs; CounterAct LT-2 Capacitive Corrosion control; LLumar AIR80 Blue clear Infra Red blocking side window film; Liftgate manual release; Schrader Valve "air in" mod to OEM air suspension reservoir tank; Akebono ceramic pads; OEM solid vented discs; LR4 design hitch receiver; Wiggs D4 MOST bluetooth module; Clock on the Dash; 3 Flash signal light mod; Backup Camera; 2015/16 Nav Data update.
20th Feb 2010 12:09 am
GraemeS
Member Since: 17 Mar 2008
Location: NSW
Posts: 706
You are correct about the front valve block, and the rear is behind the left rear wheel. The front and rear valve blocks are fed via the reservoir valve block which is fed from the compressor via the dryer without any intervening valves. The reservoir is isolated with its own valve in the reservoir valve block. With that 5A fuse removed, all valves are closed, barring mechanical faults with valves. Each air spring could be supplied with air pressure from another source on the air spring side of the front and rear valve blocks as the springs are all isolated with the ecu disabled.
20th Feb 2010 6:26 am
Spooky
Member Since: 02 Jun 2009
Location: Swindon, Wilts
Posts: 1013
I'd imagine that the 'bongs' would get annoying, but at least you could get home - quite essential in large countries where you can be miles from civilisation ...
As to the fuses and what they protect:
Link 10 (60A) - Compressor supply
Fuse 3 (5A) - Feedback to the ECU, indicating that the Compressor Relay has successfully operated
Fuse 35 (5A) - Ignition Supply to the ECU
The last of the three above will disable the system as has already been suggested.
Interestingly, the link in the first Post has a pic of an installation in a D3 ...
Click image to enlarge
Regards,
Mick
- 2014 SDV8 Autobiography
- 'Vincent' - 2010 TdV8 Vogue SE - 'Molly' - 2005 HSE Auto
'Dixie' - 2000 D2 Td5 ES
Where is the pressure regulator then - off the air tank?
I gather the air compressor runs at, and the air tank stores the air at somewhat more than +200 psig (+1400 kpa), however the air springs run more around +125 psig (+800 kps).
As such, where is the regulator that reduces the air pressure? Is the pressure reduction in the air valve just off the tank or in each of the front and rear air valves? I might add that while I knew about the existance of the front and rear air valves, the one off the tank, that was news to me, so thank you.
In the jpg of the install, I assume the piece of Land Rover kit between the battery box and the plastic reservoirs is the Fuel Burning Heater? In Canada, that space is empty as we have the petrol engine 4.4 V8's and I have a tea kettle type electric block heater installed. It is in that empty space that I was thinking of installing the FASKIT control unit; there is also an empty square hole for I suppose the the FBH exhaust that I would run the air lines thru up from below.
Re distances, if Santa Claus drives a Land Rover when the reindeers are on holiday, and his Disco starts to bong, my dealer in Alberta is his closest T4 equipped Canadian repair outlet. As Edmonton is only 400 miles, (650 km) north of the US border, Greenland or Iceland would I think be closer, so being able to "fix" the air system temporarly has some value. The sort of distances between dealers here is probably only equalled in Australia.
I think that F35 fuse should be on a switch - just removing it by the sound of things, can at times, temporarily solve or at least keep small problems from becoming bigger ones.2005 LR3 HSE 4.4L AJ-V8 petrol; Traxide Dual Battery; PIAA 2500K Yellow Ion H11 Fog Light bulbs; CounterAct LT-2 Capacitive Corrosion control; LLumar AIR80 Blue clear Infra Red blocking side window film; Liftgate manual release; Schrader Valve "air in" mod to OEM air suspension reservoir tank; Akebono ceramic pads; OEM solid vented discs; LR4 design hitch receiver; Wiggs D4 MOST bluetooth module; Clock on the Dash; 3 Flash signal light mod; Backup Camera; 2015/16 Nav Data update.
20th Feb 2010 2:55 pm
Spooky
Member Since: 02 Jun 2009
Location: Swindon, Wilts
Posts: 1013
There is no pressure reducing valve, as the pressure in the individual springs will vary with the vehicle loading. The valves simply open to allow air to the air spring, then close off again once the correct height is reached.
And yes, the is the Fuel Burning Heater in the pic, as fitted to the TdV6 models.Regards,
Mick
- 2014 SDV8 Autobiography
- 'Vincent' - 2010 TdV8 Vogue SE - 'Molly' - 2005 HSE Auto
'Dixie' - 2000 D2 Td5 ES
20th Feb 2010 4:02 pm
GraemeS
Member Since: 17 Mar 2008
Location: NSW
Posts: 706
The compressor keeps running after the air spring valves have been closed to allow the reservoir to get to its holding pressure.
No pressure regulator then - height sensor and valves do it
So the height sensors tell the computer that the "correct" height has been reached and the computer tells the solenoids to close - makes sense, and is kind of simple and works as long as the computer and valves are powered.
Back then to Fuse 35: It has occurred to me that if one say raised the Disco to off road height, or even higher to that hang up height, and then pulled Fuse 35, the air valves would stay closed and the vehicle would remain at whatever height it was regardless of ground speed - or is there something that would take over and either lower the Disco or restrict the speed?
If not, I suppose then the Land Rover could roll over just as easily as a Land Cruiser!2005 LR3 HSE 4.4L AJ-V8 petrol; Traxide Dual Battery; PIAA 2500K Yellow Ion H11 Fog Light bulbs; CounterAct LT-2 Capacitive Corrosion control; LLumar AIR80 Blue clear Infra Red blocking side window film; Liftgate manual release; Schrader Valve "air in" mod to OEM air suspension reservoir tank; Akebono ceramic pads; OEM solid vented discs; LR4 design hitch receiver; Wiggs D4 MOST bluetooth module; Clock on the Dash; 3 Flash signal light mod; Backup Camera; 2015/16 Nav Data update.
21st Feb 2010 2:26 am
GraemeS
Member Since: 17 Mar 2008
Location: NSW
Posts: 706
It will stay at off-road height, as demonstrated by others. I understand that only the warning message will be issued, rather than actually limiting speed. Someone else has already considered converting the fuse to a switch.
I have developed a comparatively cheap electronic unit that allows on-road height, +30mm and +50mm by switch position with the air suspension system believing the vehicle is still at on-road height. Probably still some weeks away yet because I'm going to have the circuit boards professionally made, but I will have them for sale as soon as I can. This way a vehicle can travel at the lowest height possible for the terrain and only be up a little or more when actually needed.
What you are designing is really interesting. Not only could it be what the off road guys are looking for, but if there is an off switch, then effectively one would have a "limp" home at normal speeds and with luck, normal height when the electronics act up.
The reason I got to looking into what the fuses do was when as it turned out, corrosion of a connector started intermittent problems to appear. The LR3 was only intermittentantly down on the stops, (stop, turn off engine, restart, and all is well for a while, sort of solution while trying to find the problem).
With an off switch re the air system computer, then at least what air is in the air springs would stay there - hence one would have a limp mode sort of, but with normal speeds possible.
Hence my question, would the control switch have what I will call an off postion? I suppose however, it would be better called a "Freeze Suspension Height" mode.2005 LR3 HSE 4.4L AJ-V8 petrol; Traxide Dual Battery; PIAA 2500K Yellow Ion H11 Fog Light bulbs; CounterAct LT-2 Capacitive Corrosion control; LLumar AIR80 Blue clear Infra Red blocking side window film; Liftgate manual release; Schrader Valve "air in" mod to OEM air suspension reservoir tank; Akebono ceramic pads; OEM solid vented discs; LR4 design hitch receiver; Wiggs D4 MOST bluetooth module; Clock on the Dash; 3 Flash signal light mod; Backup Camera; 2015/16 Nav Data update.
21st Feb 2010 3:38 pm
GraemeS
Member Since: 17 Mar 2008
Location: NSW
Posts: 706
No OFF position, only a NO-CHANGE position affecting sensor signals not the ecu, and intended for use whilst set at on-road height. There is no ability to disable or override the air suspension system in the event of a malfunction. If stuck at on-road or access height or on the bumpstops, it will not cause the vehicle to be raised because the air suspension system will not make any upward levelling height changes when malfunctioning.
IMO removing the fuse can be a good option for a system malfunction.
I read a number of your other posts and now realize that your system will be much more sophisticated and provide solutions much greater than any problem I might have. For the off road guys, it really will be smooth - just flick a switch and hit the sand.
For me, I bought the LR3 for the purpose of staying on the roads - not always that easy here in the winter.
I kind of think I will insert a switch in the fuse circuit - probably mount the switch where the passenger air bag manual turn off switch would be located - accessible when the passenger side door is open.
For the NAS models, there is no switch, only a blank snap in plastic plate so that provides a nice location for a flush mount switch. I would only be turning it off or on when the vehicle was shut down so opening the passenger door to access the switch almost makes sense.
I also wondered on what models the switch was installed - maybe the work models with no second or third row of seats?2005 LR3 HSE 4.4L AJ-V8 petrol; Traxide Dual Battery; PIAA 2500K Yellow Ion H11 Fog Light bulbs; CounterAct LT-2 Capacitive Corrosion control; LLumar AIR80 Blue clear Infra Red blocking side window film; Liftgate manual release; Schrader Valve "air in" mod to OEM air suspension reservoir tank; Akebono ceramic pads; OEM solid vented discs; LR4 design hitch receiver; Wiggs D4 MOST bluetooth module; Clock on the Dash; 3 Flash signal light mod; Backup Camera; 2015/16 Nav Data update.
22nd Feb 2010 12:29 am
GraemeS
Member Since: 17 Mar 2008
Location: NSW
Posts: 706
Re: Going to put a switch in the fuse circuit.
I think a discretely mounted switch c/w fuse is a good idea and I like your proposed switch location.. I use long nose pliers to R&R the fuse because I fear dropping the fuse behind the carpet using the supplied tool, but don't often carry my toolbox with the new vehicle so I could be caught out. No passenger airbag disable switch in my D4 either.
I was out checking for weeds in my paddocks thismorning using +30 for general driving about, often over sticks then went to +50 on the wheat stubble to stop it from scratching the vehicle and to prevent a build-up under the vehicle, without worrying about it returning to on-road height if/when I hit the speed limit. +30 gives a softer ride than +50 so that's my normal extra height.
You brought up good reasons other than sand dunes for being able to raise and hold vehicle height.
Protecting the paint and dragging stuff underneath is always a concern and got me to thinking that here on the prairies, setting dry grass or stubble on fire or smouldering is an ongoing concern.
Prior to catalytic converter equipped vehicles, it used to be we could stop and idle all day. Now however as pretty much all vehicles have converters, we pretty much have to shut the vehicle down or find some bare dirt to park on.
It can even be a problem in the winter after a chinook goes thru, melts all the snow, and exposes the dead stuff. As it is somewhat damp, it will just smolder and then a wind comes up after you have left the area and surprise, you have a prairie fire, even in the winter.
And yes, I also have a set of small long nose pliers for fuse install and removal. I dropped/lost the little fuse changer long ago and find that a flashlight and long nose pliers are the answer.2005 LR3 HSE 4.4L AJ-V8 petrol; Traxide Dual Battery; PIAA 2500K Yellow Ion H11 Fog Light bulbs; CounterAct LT-2 Capacitive Corrosion control; LLumar AIR80 Blue clear Infra Red blocking side window film; Liftgate manual release; Schrader Valve "air in" mod to OEM air suspension reservoir tank; Akebono ceramic pads; OEM solid vented discs; LR4 design hitch receiver; Wiggs D4 MOST bluetooth module; Clock on the Dash; 3 Flash signal light mod; Backup Camera; 2015/16 Nav Data update.
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