AHC challenge, need help 2000 LX470

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R

RodLX470

Joined
May 27, 2023
Threads
1
Messages
7
Location
Colorado, USA
I recently replaced all 4 actuators and the fluid with genuine fluid from Lexus. I'm following the information that I found on an IH8MUD on jumping the E1 and TS terminals on DLC1 and entering the mode to bleed air (comfort position and pushing the down button for 5 seconds, followed by pushing the up button for 10 seconds). I get the OFF indicator flashing every 0.25 seconds, but nothing happens after pushing the up button for 10 seconds. I have tested the pump motor by jumping directly to the battery and the motor functions and I can hear the motor/pump load up.

I've had this LX470 for 25 years, and I have replace actuators and fluids 3 or 4 times over the years (car has 309,000 miles and still runs fine). This is the first time that I'm struggling to get the air out if the system and getting it back to normal.

I had a broken rear height sensor, so I went ahead and replaced all the sensors, so I know that they are good.

I'm trying to set up a new Techstream instance (old computer that had it installed died), so I'm a little blind at the moment.

Anybody have any idea why I'm struggling?
 
Without TechStream you are a bit blind, yes. You could read the blinking codes instead, by connecting TC instead of TS to earth. A faulty height or temp sensor connection could tell the ECU to take a break. You could also read the voltage from each sensor on the plug of the ECU to see that the inputs are good, all the way.
 
Any thoughts on manually bleed the air from the system, since I can't get the active mode working? Can I open a bleed screw and let gravity ( or use a vacuum bleeding tool) pull new fluid into the tubing?
 
I'd just manually flush, again. Just make sure reservoir never runs dry/empty. Filter the fluid that comes out, if you'd like to reuse.

Once LH side flushed, system refilled and vehicle raised. Turn off engine, open bleeder on each right side globe, one at a time. Just open for a moment, to get air from end of globe.
 
RodLX470 said:
Any thoughts on manually bleed the air from the system, since I can't get the active mode working? Can I open a bleed screw and let gravity ( or use a vacuum bleeding tool) pull new fluid into the tubing?
Click to expand...
if there is a fault code preventing the pump from running, there is no point in bleeding -- Find the fault first. Otoh, if there is another reason for the pump not running...
I have not needed the active test for bleeding, at least not for the last 15 years. Just start it up, and bleed. There must be a reason for that pump not to start.
 
RodLX470 said:
Any thoughts on manually bleed the air from the system, since I can't get the active mode working? Can I open a bleed screw and let gravity ( or use a vacuum bleeding tool) pull new fluid into the tubing?
Click to expand...
I made a hot, hot mess in my garage trying to manually bleed my AHC a few years ago. In the end I wound up using an air-powered brake bleeder tool to make sure all the air was out, and it just pulled air out forever. Eventually all the bubbles stopped. I think there was a fair bit up in there from the old accumulators/ globes breaking down. Useful thing to have around, even though it hangs on a hook 99% of the year. It was only like $25 from Amazon, and made quick work of one-man brake bleeding on my other car, so it's got other uses.

Once you get techstream reinstalled, you'll need to use that to get your actual system pressures and stuff set. I'd bet your torsion bars need a crank or two and you might need rear springs or spring spacers to get the rear pressure closer to where it needs to be.
 
2001LC said:
I'd just manually flush, again. Just make sure reservoir never runs dry/empty. Filter the fluid that comes out, if you'd like to reuse.

Once LH side flushed, system refilled and vehicle raised. Turn off engine, open bleeder on each right side globe, one at a time. Just open for a moment, to get air from end of globe
Click to expand...

wrigh003 said:
I made a hot, hot mess in my garage trying to manually bleed my AHC a few years ago. In the end I wound up using an air-powered brake bleeder tool to make sure all the air was out, and it just pulled air out forever. Eventually all the bubbles stopped. I think there was a fair bit up in there from the old accumulators/ globes breaking down. Useful thing to have around, even though it hangs on a hook 99% of the year. It was only like $25 from Amazon, and made quick work of one-man brake bleeding on my other car, so it's got other uses.

Once you get techstream reinstalled, you'll need to use that to get your actual system pressures and stuff set. I'd bet your torsion bars need a crank or two and you might need rear springs or spring spacers to get the rear pressure closer to where it needs to be.
Click to expand...
 
I went ahead and got an air powered bleeder, quite an improvement over my old handheld bleeder. However, I'm only getting a drop of fluid out of all four globes and the reservoir doesn't drop. Quite a mystery. The bleeder screw on the accumulator was broken off, so I've got to work to get that our and replace the screw before I can bleed the accumulator.
I finally go the XP laptop that has Techstream on it running, but so far I can get Techstream to connect to the car. I used this setup a couple of years ago and it did connect and I was able to balance the front and rear pressures and heights using the information from Techstream.

Onward through the fog.........got to figure out why the fluid is not bleeding.....
 
Sounds like there is air in the pump itself, maybe dirty screens inside pump and/or the pump just isn't working for some unknown reason.

I just had a similar situation where the globes would not produce any pressure or fluid but motor would runwith direct power then motor decided not to run. I bench tested and it would not deliver pressure or fluid much at all even after cleaning all three screens. I changed out the motor/pump assembly with a spare one I had and everything came to life and working fine. I was getting fault code 1762 which is no fluid pressure. New pump delivered pressure and now all good.
uHu said:
if there is a fault code preventing the pump from running, there is no point in bleeding -- Find the fault first. Otoh, if there is another reason for the pump not running...
I have not needed the active test for bleeding, at least not for the last 15 years. Just start it up, and bleed. There must be a reason for that pump not to start.
Click to expand...
As @uHu asked.....Is there no fault code showing up?
 
I've had more than one come to after DIY flush.
In some they just failed to close all (5) doors
In some it was a case where they, let reservoir run dry. Because they'd not pouring in the whole 2.5L tin of fluid.
In some they use AHC fluid from plastic bottle, that jelled
In some they ran pump dry for too long, and burn up the pump.

If you would like stop by. I'll take a look.

But first place a light behind reservoir. So you can see its level. Many see a stain line, and end up under filling.
Then start engine, set AHC in L, close all doors and give it a few minutes to raise to L.
 
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