LX570 AHC “Basics” - Added as sticky thread for AHC Issues

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Hey all, got a new to me LX570, 2019 with 23k miles. Changed the AHC fluid and set AHC Height Offset to Zero via Techstream.
The AHC fluid bleed is really straight forward. I definitely overthought it. Didn't end up changing the 5th accumulator, got lazy.

Curious what the best way to set the height is.. AHC sensors, Techstream, or Torsion?

Factory spec says:
19.75 front
20.5 rear

I measure:
the driver side (left) is lower than the passenger (right)
Front L: 19.75
Front R: 20.5 - passenger
Rear L: 19.75
Rear R: 20.5 - passenger

Thinking I should adjust the physical sensors based on the Height Control Sensor readings - all different numbers
AHC.webp
 
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guy80 said:
Hey all, got a new to me LX570, 2019 with 23k miles. Changed the AHC fluid and set AHC Height Offset to Zero via Techstream.
The AHC fluid bleed is really straight forward. I definitely overthought it. Didn't end up changing the 5th accumulator, got lazy.

Curious what the best way to set the height is.. AHC sensors, Techstream, or Torsion?

Factory spec says:
19.75 front
20.5 rear

I measure:
the driver side (left) is lower than the passenger (right)
Front L: 19.75
Front R: 20.5 - passenger
Rear L: 19.75
Rear R: 20.5 - passenger

Thinking I should adjust the physical sensors based on the Height Control Sensor readings - all different numbers
Click to expand...

why are you messing with AHC if she only has 23k miles? Just drive her and enjoy :)
are you sure you're on completley level ground when you measured the corners?

You also said you "set the height offset to zero" in techstream. why did you do that? that could be why your measurements are off.
 
guy80 said:
Hey all, got a new to me LX570, 2019 with 23k miles. Changed the AHC fluid and set AHC Height Offset to Zero via Techstream.
The AHC fluid bleed is really straight forward. I definitely overthought it. Didn't end up changing the 5th accumulator, got lazy.

Curious what the best way to set the height is.. AHC sensors, Techstream, or Torsion?

Factory spec says:
19.75 front
20.5 rear

I measure:
the driver side (left) is lower than the passenger (right)
Front L: 19.75
Front R: 20.5 - passenger
Rear L: 19.75
Rear R: 20.5 - passenger

Thinking I should adjust the physical sensors based on the Height Control Sensor readings - all different numbers
View attachment 3979448
Click to expand...
The 570 doesn't have torsion bars fyi
 
radman said:
why are you messing with AHC if she only has 23k miles? Just drive her and enjoy :)
are you sure you're on completley level ground when you measured the corners?

You also said you "set the height offset to zero" in techstream. why did you do that? that could be why your measurements are off.
Click to expand...

The tank was low, when I put it in High there was NO fluid in the reservoir.
The fluid was pretty dark but not solid black as some photos online. Also got quite a bit of air out of the lines.

Level ground is a good question. Probably not. Just a garage floor.

I tried to adjust the corners in Techstream before the fluid change and didn't measure any difference. Figured I better start from zero at this point.
 
Curious if anyone had this issue with easy access not dropping the rear? It drops front to L only.

Manually cycled through H-N-L works fine.
 
m12345y said:
Curious if anyone had this issue with easy access not dropping the rear? It drops front to L only.

Manually cycled through H-N-L works fine.
Click to expand...
I will have to look, I never noticed if the rear drops as well. It drops the rear also, though not much.
 
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I find that easy access drops the entire vehicle to its L setting rather quickly. I’ve never experienced just the front dropping, but after doing globes last week, it’s definitely slower (more back pressure from the nitrogen in the globes). You shouldn’t have to change the 5th accumulator. It’s for height adjustment and I think i read it’s a non-wear part; it either works or it’s broken.
 
Yeah, I believe it used to drop the entire vehicle but now just the front, still drops pretty fast though.

On manual height adjustment it also drops the entire vehicle from N to L pretty fast.

I rarely use the vehicle except for trails and trips, I guess I will drive it more to see if the problem persists.
 
m12345y said:
Curious if anyone had this issue with easy access not dropping the rear? It drops front to L only.

Manually cycled through H-N-L works fine.
Click to expand...
as someone who just changed fluid, the rear drops, but it feels very subtle sitting in the car
I had to measure it to confirm

also takes only 12 seconds to go from L to N after the fluid change, compared to 17-23 seconds
 
My 2019 LX recently passed 60k, and I asked the dealer about changing the AHC fluid. They recommended against it, said it would cause more trouble than it would save. Aside from the shock of a dealer turning down potential work, what do you guys think of this advice? Doesn't seem like that difficult a procedure. (Yeah I know, I could read the previous 800+ posts...)
 
BigSwede said:
My 2019 LX recently passed 60k, and I asked the dealer about changing the AHC fluid. They recommended against it, said it would cause more trouble than it would save. Aside from the shock of a dealer turning down potential work, what do you guys think of this advice? Doesn't seem like that difficult a procedure. (Yeah I know, I could read the previous 800+ posts...)
Click to expand...
Sucky advice from a stealership who clearly doesn’t know its own products. Get a new dealer or better yet, find a competent independent shop. And yes, change the AHC fluid, including the tranny.
 
I think I need to change my AHC fluid.

Sometimes when I start driving one side will stay lower than the other, like majorly! So much so that my steering wheel is turned to one side to keep it driving straight. It seems like one side stays in low and the other in normal. And it's random.
 
BigSwede said:
My 2019 LX recently passed 60k, and I asked the dealer about changing the AHC fluid. They recommended against it, said it would cause more trouble than it would save. Aside from the shock of a dealer turning down potential work, what do you guys think of this advice? Doesn't seem like that difficult a procedure. (Yeah I know, I could read the previous 800+ posts...)
Click to expand...
 
That is terrible advice. You absolutely want to change the AHC fluid >60k. I did mine after acquiring it with 89k miles. There was air in the lines and fluid was pitch black. The ride was "bouncy" when I first got it. Changing out globes and fluids made a big difference. You can change out the fluids yourself. Takes a few hours, but well worth the time. $80-$100 for Toyota AHC fluid.
 
I would avoid that dealership for anything in the future. AHC is a service item, it is in the maintenance guide, every 60k miles.

If you follow the threads here on bleeding (or on changing accumulators, still have to bleed) it is a pretty straightforward job. Get a decent hand pump to fill the reservoir and good light to see the level. Also, a stubby 10mm wrench will make access to the bleeders easier. If you have ever bleed brakes it's a very similar process.
 
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Our LX has its 60k service coming up and since we recently bought it as a CPO the next 4 services are free. This tempting me to have the dealer perform the 60k maintenance which includes all the big fluid changes. I’m torn for a few reasons, mainly because I prefer to do my own maintenance but I’ve heard tell of a couple good Lexus dealerships, I’m going to call around and make sure they will flush the tranny and AHC as required in the maintenance manual.

2 questions for the group are:

1. Should I just do this myself? The cost savings of the free services is tempting as the fluid alone for the t-case, AHC, and transmission really add up.

2. Should I have the AHC service done before installing the 24 gallon LRA that’s now sitting in my gym?
 
Artie said:
Our LX has its 60k service coming up and since we recently bought it as a CPO the next 4 services are free. This tempting me to have the dealer perform the 60k maintenance which includes all the big fluid changes. I’m torn for a few reasons, mainly because I prefer to do my own maintenance but I’ve heard tell of a couple good Lexus dealerships, I’m going to call around and make sure they will flush the tranny and AHC as required in the maintenance manual.

2 questions for the group are:

1. Should I just do this myself? The cost savings of the free services is tempting as the fluid alone for the t-case, AHC, and transmission really add up.

2. Should I have the AHC service done before installing the 24 gallon LRA that’s now sitting in my gym?
Click to expand...
Dealers kill more cruisers than anything else. D.I.Y.
 
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