Vehicle: 2005 LR3 with 79k miles
Problem: Air suspension will not raise, vehicle is low to the ground

Hey guys, I would like to know if there is a way to pressurize the suspension.
Over the past few months I have gotten a few suspension fault messages and finally it's just kaput. My vehicle is now stuck in the lowest mode and I cannot raise the vehicle with the switch. Can manually make the compressor pressurize they system? I really don't want to take this vehicle to the shop, I just spent 4k on cooling system and radiator work, since the vehicle is 10 years old with 79k miles, spending another 4k-6k on it just isn't something I want to do. Other than this suspension system issue, the vehicle doesn't have any issues, I have regularly taken the vehicle to the shop for issues.
I don't believe that there is any problem with the vehicle maintaining or pressurizing. It will raise but when the fault occurs the vehicle lowers all the way, now it wont even do that.

I was hoping I could connect a jumper to the compressor relay to turn the compressor on and raise the vehicle.

I do have the workshop manual and saw it requires the T4 unit to pressurize and depressurize, but there has to be a wiring solution I could use to just make the compressor switch on.

Many thanks in advance.

 

Absolutely not. The air suspension is so highly integrated into the vehicle and computer systems that if you don't plan on shelling out the $$ for diagnostics equipment or taking it to the shop, you should really get rid of the vehicle.

There are a number of independent valve blocks that must open and close to redirect air through a specific path into the appropriate air bags. If you manually energized the compressor it would just damage something as the control valves and air pathway would be closed anyways.

Usually it'll direct air to inflate the air tank, NOT directly into the air bags (unless there's only a small adjustment that is required, in which case it can bypass the air tank and fill the suspension independently).

It's not like the DII SLS system, but even that one would require one of the rear bag control blocks to open to provide a path from the compressor to the bag.

Hope this helps, probably not what you wanted to hear though.

edit: even if you fooled the system, the computers would know the height of the vehicle and in its limp/access fault mode would probably simply dump air out of the suspension again anyways!

 

Yeah I kinda figured it wouldn't be simple, my perfect streak of bad luck sees to that, LOL.

Thanks for the info.

I do plan on getting rid of it at the end of the year, haven't figured out the best method yet, pushing it off a cliff or shooting it into space.

 

Clearly the latter....if you do it right it can be the next "Mars Rover."

 

I tried to get our part truck suspension up today and even with clearing codes with my scanner it was no go, I could get compressor running but I hear an air leak at compressor and kept tripping same fault

 

Well, it sounds like you need a compressor.

There is a way to setup a backup in these cases, bbyer has done it, and is an authority on the subject. It's not something you are going to just slap together, but it would be a nice backup in case of a failure.

As I understand it, the solution has 3 main segments.

1. A switch to disable the compressor / air suspension system if there is a problem.
2. A Schrader air valve installed on the air tank (in my case a big PITA) as I have sliders.
3. A FASTkit air suspension components and related fittings and lines.

In summary, if there is a problem, disables the electronics/auto leveling components, the manual ability to "air up" the tank, and bring the suspension off it's knees.

 

Option 4, get an arduino, become very familiar with programming, splice into all valves, and compressor wires, and create your own computer controlled air system. One that only listens to your inputs.

For the record, my friend who is a huge arduino fan, really wants to build this set up for my LR3, so I guess I will report back if anything comes of it

 

I'll buy you the hardware. Let's make this happen!

Dave

 

I take that back.

I was driving home the other day and recalled a situation in my DII where I would have been able to continue a road trip to a ski resort at night through mountains if I had a couple parts with me. As it was, a leak got so bad the computer gave up, threw a code, and stopped inflating (I had a Viair compressor at the time so it was no worries). I was pissed, and had to go home.

Yes, if you can correctly identify the front left & right hoses, and the rear left & right hoses, combine each into a tee fitting with a schrader valve, you can inflate each axle pair independently.

Doesnt' matter what the computers and screens are bitching about, it won't be able to disable anything since it's manually raised.

 

Actually it easier than teeing into the airlines, you only have to identify the solenoid valves for each bag, and the valve to the air reservoir and the valve for exhaust. Splicing into the wires for these valves will allow you theoretical control over inflating and deflating of your bags just like the LR3 would. The only real snag would be ride height feedback. You would either have to have a gap IID to read rode height or a spotter telling you when you are roughly even