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bbyer
Member Since: 25 Dec 2008
Location: Edmonton Alberta
Posts: 702
  
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| Air Suspension ECU F35 fuse circuit switched. |
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Thanks to the accurate information provided by Spooky and GraemeS, I have installed a switch in the Air Suspension ECU F35 fuse circuit located in the fuse box behind the lower glove box.
In my gallery, I have a jpg showing the installed switch which I located in the blank knockout on the end of the dash where it appears a manual passenger air bag switch could be located. All I did was remove the 5 amp fuse from location F35 and install a Littelfuse Add-A-Fuse adapter and then run a 16 gauge conductor to and from a spst switch.
The idea is that should the air system wiring, wheel level sensors, or something in the electical circuit fail, turning the switch off would remove power to the air spring air line valves. Upon loosing power, the valves fail closed and that traps whatever air is still in the airsprings. The concept is that with the valves deactivated in a closed postion, that the vehicle would at least not drop down to the stops, assuming that it was not already there. If it was, then depending upon what has failed, sometimes the vehicle will raise off the stops upon startup assuming the air compressor and air spring / air lines are OK, and that would allow one to shut the valves off once desired height had been achieved. I might add that just removing the F35 fuse does the same thing and without the fuss of a switch and wiring. Installing the switch just shut off easier in the dark and cold.
I drove around a bit today the vehicle height at normal city driving elevation and the switch in the off position - that is no power to the air valves. I turned the switch off prior to starting the LR3, but with the vehicle at normal height, (not access).
Upon start up, I noted that there was no illumination of the line re the vehicle height control lever for about 30 seconds. Then there was a bong, the yellow suspension trouble light at the bottom of the tach lit up, there was the air suspension failure message in the display, and the "normal height" line illuminated at the lever switch down on the console. The 4x4 Info display showed all four wheels to be in line with the axle as they should be.
When driving, other than the yellow suspension trouble light being on, all seemed about normal. There was the sound of a single bong about 30 seconds after engine start, but after that, there was no more bonging or suspension messages.
I felt that perhaps the ride on City paved potholed winter streets was a bit rougher, (less smooth and more harsh than normal), but that may have been my imagination. I also think that the wheel depiction on the 4x4 display was what I call frozen. I think when all is normal, there is a bit of bobbling on the display, but with the F35 power off, the wheel display did not move at all, but showed normal height.
While a few weeks may change my thoughts, for the moment, I think the installation of the switch is a success and it does what I had hoped it would - that is give me the chance to avoid going down to the stops upon failure of the electrics related to the Air Suspension ECU and wiring.
Incidentally, it appears that GraemeS is working on a circuit board that I think ties into the ECU wiring, and gives one manual control of the vehicle height - or at least manual control over the automatic lowering function. This ability to gain further control over the air system has real value.
With the challenges Toyota now faces, we may eventually see vehicle on board computers at least dealer reprogrammable. We are more fortunate with our Land Rovers as a lot of the vehicle systems are already upgradeable, either by the dealer, or better yet, if one has access to revised software and a unit such as the Black Box reprogrammer, by the vehicle owner. 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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 25th Feb 2010 2:25 am |
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discos_galore
Member Since: 23 Mar 2010
Location: Western Victoria
Posts: 8
  
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I pulled fuse 35 as my 2005 D3 keeps on wanting to lower to the bump stops at speeds over 75km/h. Unfortunately it still lowered. I'm 300 km from my nearest dealer. looks like it will be a slow trip. 
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| 15th May 2010 9:20 am |
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GraemeS
Member Since: 17 Mar 2008
Location: NSW
Posts: 706
 
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discos_galore,
With the suspension still up, I would remove the compressor cover and unplug the electrical connectors to prevent the exhaust valve from being opened.
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| 15th May 2010 9:36 am |
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discos_galore
Member Since: 23 Mar 2010
Location: Western Victoria
Posts: 8
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GraemeS wrote:discos_galore,
With the suspension still up, I would remove the compressor cover and unplug the electrical connectors to prevent the exhaust valve from being opened.
thanks i will try that tomorrow.
I am interested in your suspension switching mod you speak of.
I have fitted a set of toddco spacers and are thinking the original rods with your doodah could be better than the rods provided by toddco.
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| 15th May 2010 11:09 am |
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bbyer
Member Since: 25 Dec 2008
Location: Edmonton Alberta
Posts: 702
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| Can also pull Fuse 3E and Fuse 26E in the Engine Compartment |
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Yes, removing the power from the compressor may stop the air from venting as there are air release valves kind of within. There are howver two power connectors coming off the compressor assembly, one that powers the compressor motor and the other connector that powers the pilot exhaust valve and temperature sensor.
A perhaps easier way to remove power is from within the engine compartment. There is that fuse panel located near the battery. Inside there is a 5 amp fuse, Fuse 3, and also Fuse 26, a 20 amp fuse, and also a 60 amp fuseable link for the compressor power.
Fuse 26 provides full time battery power to the ECU and Fuse 3 is some sort of control circuit between the compressor and the ECU. These two fuses seem to be what contols the "after hours" self levelling. In other words, it is these fuses that provide power to the air release valves when the 3 is shut down and parked and you get that self levelling "fart" every so often.
Removing the 60 amp fuseable link that provides power to the compressor should shut the compressor down, however I presume you first need the compressor alive to pump up the 3. I assume that the problem is that after the 3 gets to proper level, it then subsequently, dumps. This is good in that once up, you can remove the fuses etc.
If the system actually dumps the air rapidly, then pulling the F3E and F26E as well as the F35P, (ignition power), should kill all the auto dump circuits; if there is a mechanical leak such as an air line, air spring, or within the air release valves near the compressor, then pullling fuses will not help.
We will be interested to know what the solution to the problem eventually was. 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.
Last edited by bbyer on 15th May 2010 10:17 pm. Edited 1 time in total
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| 15th May 2010 1:27 pm |
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GraemeS
Member Since: 17 Mar 2008
Location: NSW
Posts: 706
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Thanks bbyer. I was too lazy to lookup the D3 wiring diagram for which fuse(s) to pull and D4 fuses aren't necessarily the same as the D3.
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| 15th May 2010 8:46 pm |
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discos_galore
Member Since: 23 Mar 2010
Location: Western Victoria
Posts: 8
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| Re: Can also pull Fuse 3E and Fuse 26E in the Engine Compart |
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Thanks fellas. I pulled the F3E and F26E as well as the F35P and took it for a test blast. Sits on the road happily and doesn't dump air at highway speeds like it had been. The car seems to maintain height no probs so i don't think there is a leak in the system. My guess is a height sensor has chucked a wobbly or, i have read somewhere that wheel alignments can create problems, which coincidentally i had done the week before last and the first time after that that I tried to get up to highway speed it cracked em.
It was due for a service anyway so i'll let you know the result. 2005 Disco 3 TDV6 SE - LR Nudge Bar, winch carrier protection plate. Light Guards. Ironman 12000 lb winch. 17" Dynamic Steel D3 rims. Cooper STT's - 265/70-17. ARB CMKA12 compressor. Home made ($30) D3 air off. Traxide SCLR-40 dual battery kit / Optima Yellow Top D34. Home made AUX audio line in. No 'you've forgotten your seatbelt' alarm. Rear power sockets and battery level monitor for 2nd Battery. Safari Snorkel. Toddco 50mm spacers/Air Suspension lift kit + Battle scratches thanks to me.
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| 16th May 2010 1:20 am |
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bbyer
Member Since: 25 Dec 2008
Location: Edmonton Alberta
Posts: 702
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| Corroded or ripped offwire perhaps and a field fix verified! |
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That is good news - that removing all the fuses seems to kill off the "down to the stops" programing, and that the 3 still runs. I wondered if there was some sort of deadmans switch in the software put there just to frustrate that sort of field fix.
I got my part of my education on this stuff about Christmas time.
I / dealer assumed the problem was one of the front wheel sensors so I had them change both of them plus about 6" of the multi conductor and the plug that connects to the sensors. Land Rover has a repair kit out for this, as the last 6 inches of wire I guess goes bad on the 2005 models.
Well this repair was good for a couple of weeks and then same thing - suspension lights and the 4x4 display showing the same bad front right wheel problem - the wheel bounced up and down on the display, but not actually on the vehicle.
This time they replaced some lengths of sensor cable where the 3 plugs come together kind of in the front left wheel well. I think I have it explained in a previous post in this thread.
Anyway, that fix worked pretty good for another two weeks, and again, same story. (I am now not happy.)
Anyway, for some reason, I raised the 3 to off road height and looked at both the front wheel sensors. Surprise, the cable portion that feeds into the right front sensor I guess got loose and somehow got hooked by the tire sidewall and was ripped off.
Dealer fixed for free and this time, the cable to the sensor was carefully tied back to the frame with snap ties - and on both sides. All has been well since.
Anyway, what I am saying is to look at the wiring where it joins the sensors., both front and rear - one cable may just be ripped off. Also if you have the GPS setup with the 4x4 wheel display, keep an eye on it. You have to have the fuses in the circuit however, but it might indicate where the computer thinks the problem is - like all computers, the indication may be just to send you looking in the opposite direction.
Overall, I think a field fix has just been verified, and you had the "pleasure" of being the lead candidate in the testing process. 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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| 16th May 2010 1:46 am |
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bbyer
Member Since: 25 Dec 2008
Location: Edmonton Alberta
Posts: 702
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| opportunity to experiment here |
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When you get back and are about to take your 3 in, consider installing the F3E fuse back in the circuit.
There is a thought on my part that the F3E powered circuit may not effect the exhaust valve, (even though I said to pull it). I think the F3E fuse power provides more of an information feedback to the ECU rather than having anything to do with the exhaust valve. If when back in the circuit, the 3 does not drop with the F3E fuse back in, then try putting the F35P fuse also back in.
Your experience suggests that removal of the F35P fuse does not totally override control of the exhaust valve or the wheel block valves when the 3 is running. This is a bit of a surprise to me as I thought it did, but it appears that the auto levelling, (or something - for certain the dump), function powered by F26E is operational not only when the 3 is shut down and parked, but also when the 3 is in operation.
I would say that for certain your experiences tells us that to prevent the 3 going to the stops, the F26E fuse has to be removed. I also think the F35P fuse must be as well, (but still a question), and re the F3E, fuse, I kind of doubt it even thought I said to do so - but it is still a question in my mind. 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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| 16th May 2010 1:21 pm |
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bbyer
Member Since: 25 Dec 2008
Location: Edmonton Alberta
Posts: 702
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| Ever determine what the fault was? |
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I just wondered what the suspension fault ultimately turned out to be; also did pulling the F26e and F3e fuses keep the 3 from lowering? 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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| 5th Jul 2010 2:23 am |
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caverD3
Member Since: 02 Jul 2006
Location: Oberon, NSW
Posts: 6922
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| Re: Air Suspension ECU F35 fuse circuit switched. |
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bbyer wrote:
I felt that perhaps the ride on City paved potholed winter streets was a bit rougher, (less smooth and more harsh than normal), but that may have been my imagination.
Not your imagination, mine had a fault and did the same. Feels like a tall go-kart with much less compliance in the suspension. I still did a 500km round trip icluding some far tracks and paddocks with it.
 Try switching off the fuse when in off road height. I think you will find it will stay in off road height. If you use this too often you will find fault codes will build up in the system as it logs one each time you do it. “There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely gamesâ€
Ernest Hemmingway
D4 3.0 Active Diff, Adaptive Lights, High Beam Assist, Surround Cameras, Privacy Glass.
D3 2.7:Adaptive Headlights,Electronic Rear Diff,ARB Bar,Blaupunkt Speakers,JVC Powered Subwoofer,Removable Snorkel,Mitch Hitch,Pioneer After Market Head Unit,Steering Wheel Control Adaptor,Remote Adjustable Supension Rod System, Taxside Dual Battery System.
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| 5th Jul 2010 3:17 am |
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cazz
Member Since: 05 Jul 2010
Location: sheffield
Posts: 7
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my disc 3 HDC keeps coming on and the air suspention lowers to the bottom and its now letting bits of air out any advice
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| 6th Jul 2010 11:05 am |
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bbyer
Member Since: 25 Dec 2008
Location: Edmonton Alberta
Posts: 702
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| Changed any tail lights or spilled coffee? |
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You are saying that the Hill Decent Control is coming on for some reason and then the 3 drops to the stops.
This sounds strange, but then again, most all of these suspension faults have that characteristic.
In general, the fault is probably wiring related, not that that helps you much.
Re above, I was wondering if you have installed any new or have burned out tail light bulbs. It appears that defective bulbs will display as unrelated faults. A failed filament within a bulb can fall onto a second internal filament and the computers pick the "short" up as some sort of drivetrain fault and respond accordingly.
Also there can be a fault within the control buttons or levers in the console, say by spilling liquids into them, and then warnings start to show up.
The 3 going down to the stops is Land Rovers equivalent to a computer going into Safe Mode - the intent is to protect both you and the vehicle, so do not read too much into that.
If the compressor still works and you can get the 3 up to a proper driving height, then pulling the fuses, F35p, F26e, and maybe F3e will tend to keep the 3 from dropping so that you can drive the vehicle to a dealer or have the time to trouble shoot the wiring yourself.
You might want to look in my gallery in the picture section related to my Schrader Valve install in the Air Tank. That is my attempt to get air into the tank upon compressor failure - the assumption being that the rest of the system still works - not true in your case by the sound of things. 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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| 6th Jul 2010 1:31 pm |
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caverD3
Member Since: 02 Jul 2006
Location: Oberon, NSW
Posts: 6922
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Take the compressor cover off and have a look at where the dryer meets the compressor. If the decicant gets wet it can cause air to blow from the seal at that spot. “There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely gamesâ€
Ernest Hemmingway
D4 3.0 Active Diff, Adaptive Lights, High Beam Assist, Surround Cameras, Privacy Glass.
D3 2.7:Adaptive Headlights,Electronic Rear Diff,ARB Bar,Blaupunkt Speakers,JVC Powered Subwoofer,Removable Snorkel,Mitch Hitch,Pioneer After Market Head Unit,Steering Wheel Control Adaptor,Remote Adjustable Supension Rod System, Taxside Dual Battery System.
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| 6th Jul 2010 9:21 pm |
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cazz
Member Since: 05 Jul 2010
Location: sheffield
Posts: 7
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hi yes there was a side light out which i have now replaced and the HDC has syoped coming on i have also removed fuse 35 which as stoped the air coming out how safe is the car without fuse 35 as we pull a horse trailer? Thank you for all the help
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| 7th Jul 2010 10:46 am |
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