2004 LX; Several Problems; Air Suspension, Emergency Brake & Sideview Mirror (1 Viewer)

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Jan 20, 2008
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Hi everyone,



Hope all is well.



2004 Lexus LX470 here.



Couple problems:



1. Air suspension appears to be at normal ride height, but the instrument cluster indicator states LO, and OFF in orange keeps blinking.



2. The emergency brake indictor in the instrument cluster randomly remains lit and randomly appears on and off.



3. The passenger side view mirror makes a continuous motor sound (from the folding feature, not the mirror glass) without even attempting to fold the mirror in. Which fuse can I pull to stop this? I’ve tried folding the mirror in, folding it out and in all ways, but to no avail.



Your kind assistance would be greatly appreciated.



My best.
 
couple answers/suggestions:
1
Get hold of TechStream, read codes, fix AHC system. Could be that the neutral pressure has not been adjusted lately or a bad height sensor, e.g.
2
The warning light for brakes is a combined light, it's not exclusively for the E-brake. Could be a bad hand brake switch, low brake fluid, or a failing brake booster, e.g.
3
Don't know. Read the FSM.

1641082393815.png

1641082411712.png
 
Thank you very much, uHu.



Brought the truck to a shop.



1. Ended up giving it back to me stating they don’t do suspension work, when I know they do (they’ve worked on this truck before!). I think they just don’t want to delve into it. So I brought it to another shop. Hopefully just a sensor, but can you tell me: Why would the Neutral pressure need to be adjusted? Does that go out of adjustment for some reason?



2. First shop ended up adding brake fluid and it seems to have resolved the BRAKE light. Question: If there was low brake fluid, does that mean that there is a leak somehow / somewhere?



3. What does FSM mean? Unfortunately, the shop simply disconnected the plug to the mirror, it stopped making the folding motor sound, but now I’m unable to control the positioning of the mirror. Argh.



Thanks again!

IMG_7729.jpg
 
Further note:

When I press the up button on the suspension, I see the truck very, very briefly begin to slowly raise and then stop.

The light then goes from blinking Neutral back down to Lo.

Not sure if that indicates anything in particular.

Hopeful that that at least means that the pump works.
 
Question: If there was low brake fluid, does that mean that there is a leak somehow / somewhere?
As brake pads wear down, the pistons in the brake calipers extend out, drawing in brake fluid from the reservoir.
 
Thank you, hoser!

Haven't heard back from second shop yet re. suspension; hopefully just a sensor and nothing major.
 
Shop got back to me stating they 'think' it's the 'module' that 'controls' the suspension.

I asked if it could be a sensor, but they said no, that it's not a sensor.

They're talking in the area of $1,600 just for the part!!! :(

Anyone know what the part number is for the 'module', and if there's anything in particular I can say to them or ask of them to confirm whether or not it is in fact the 'module'??? Argh. :(

Please help.

Thank you very much.
 
It's a 2004 LX 470 with nearly 200k miles on it. Thank you.
 
Further note:

When I press the up button on the suspension, I see the truck very, very briefly begin to slowly raise and then stop.

The light then goes from blinking Neutral back down to Lo.

Not sure if that indicates anything in particular.

Hopeful that that at least means that the pump works.

Sounds like it's simply over pressure. The AHC system requires occasional adjustments to the torsion bars and potentially rear spring replacement over time. Very simple, relatively inexpensive and almost never done.
Shop got back to me stating they 'think' it's the 'module' that 'controls' the suspension.

I asked if it could be a sensor, but they said no, that it's not a sensor.

They're talking in the area of $1,600 just for the part!!! :(

Anyone know what the part number is for the 'module', and if there's anything in particular I can say to them or ask of them to confirm whether or not it is in fact the 'module'??? Argh. :(

Please help.

Thank you very much.
They don't have a clue. ;)

Here's something critical to know about AHC: Almost all shops are completely clueless and that even includes Lexus dealers. AHC as is in the LX is very rare - only offered in the LX and not in any other model. Most techs haven't seen it and those that have probably didn't' spend enough time with it to retain anything from it.

Start here: Hint, you NEED techstream or another means of reading parameters from the ECU.

 
I was waiting for @suprarx7nut to reply on the suspension stuff. Start with that video and you will know very quickly where the issue is. I can pretty much guarantee no "module" is mis-behaving. It is very likely to be the high pressures or the globes are at the end of their life.
 
Thank you both, suprarx7nut and lassyJalopy so, very, much!

Truly a wealth of info; and just in the nick of time.

Truck still at the shop; I e-mailed them all that you’ve stated along with the video.

Hopeful they’ll be able to get down to the bottom of this and sort all out.

Question: Is techstream absolutely needed or can another program be used?

I ask because I’m unsure if this shop has techstream.

Any way to obtain it for free if the sole program needed?

Thanks so much. Can’t thank you enough!
 
Thank you both, suprarx7nut and lassyJalopy so, very, much!

Truly a wealth of info; and just in the nick of time.

Truck still at the shop; I e-mailed them all that you’ve stated along with the video.

Hopeful they’ll be able to get down to the bottom of this and sort all out.

Question: Is techstream absolutely needed or can another program be used?

I ask because I’m unsure if this shop has techstream.

Any way to obtain it for free if the sole program needed?

Thanks so much. Can’t thank you enough!
If you're an expert and you already know all the parameters and what they mean you could probably get by with a third party tool. If you're new to it, Techstream makes it way easier.

I have not seen a third party app display all the AHC parameters on one page. Techstream offers that and it's a big help.

Techstream is available cheaply from Amazon and ebay (all pirated) and also for free from many places (techstream in 5 minutes on here). If you have the VCI cable and a windows laptop you're only a few minutes away from operational.

Of course, the correct way to get Techstream for a shop would be to buy it. $1300/year if I recall correctly. Obviously not feasible for a shop that never needs it, but if they work on Toyota/Lexus mostly then they should probably already have it.
 

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