LX570 AHC “Basics” - Added as sticky thread for AHC Issues (9 Viewers)

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lx200inAR said:
Mileage wise, the globes are probably okay-ish. But seems like age in this case would be as important as anything else. I wouldn't rule out globe replacement. Especially if you possibly blew one and that's why your ride is significantly worse now. Definitely sounds like something is wrong if you had a large change in damping. If you are in sport mode, do you get the same wallowing in dips?
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It's similar in sport mode

I was thinking the same thing as far as age vs mileage.

I suppose there's no harm in doing a flush first right? Wouldnt the ideal order would be flush THEN globes anyway?
 
ROMR NTX said:
It's similar in sport mode

I was thinking the same thing as far as age vs mileage.

I suppose there's no harm in doing a flush first right? Wouldnt the ideal order would be flush THEN globes anyway?
Click to expand...
You’re basically doing a flush when you replace the globes.
 

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  • AHC-AVS for LX570 - General Description and Diagrams.pdf
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Thanks all, actually I am in the process of fighting South Bay Lexus in Torrance, because the AHC fluid service I asked for according to them only includes draining the AHC reservoir and adding new fluid into the reservoir even though I asked for a flush and compared it to bleeding a brake system.

The Service Manager wants me to provide the dealer shop section that shows the bleeding process (Pretty sure he assumes I won't do it)

Anyway I should of just spent the few hours of research to drain and replace the fluid myself. Lesson learned. I am attempting to A) Get a full refund, around $375 or B) Ask nicely to have the service done. I even have texts of the Service Advisor confirming it will be a flush.
 
chriscosta416 said:
The Service Manager wants me to provide the dealer shop section that shows the bleeding process (Pretty sure he assumes I won't do it)
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page 278 of the document i linked earlier...


1660801536914.png
 
2009 LX here with 208K on the clock. I am experiencing a 2"lean to the left. The left side height measurement is 2" less than that of the right side on both wheels. I have recently changed the fluid and nothing changed. I do have the sensor lift on 33s. Is this something I will need a techstream to calibrate? any other comments?

Found earlier where someone had to recalibrate the VSC system using instructions from the FSM. does anyone have those instructions handy?

TIA
 
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SpillmanCruiser said:
2009 LX here with 208K on the clock. I am experiencing a 2"lean to the left. The left side height measurement is 2" less than that of the right side on both wheels. I have recently changed the fluid and nothing changed. I do have the sensor lift on 33s. Is this something I will need a techstream to calibrate? any other comments?

Found earlier where someone had to recalibrate the VSC system using instructions from the FSM. does anyone have those instructions handy?

TIA
Click to expand...

I feel like that may have been my post. How does your truck react when cycling through the height settings? If you'd like to see the FSM procedure, I can pull those for you, but you're going to need Techstream to do anything.

Do you have any leaking shocks?
 
It was your post. Gotcha. I will try to get under and look at possible leaks this weekend. It has rained every day down here for 2 months so it may be hard to tell.

Cycling height is no problem but I need to measure in each stage to see if the 2" difference persists. I will report back
 
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joesrcool said:
I feel like that may have been my post. How does your truck react when cycling through the height settings? If you'd like to see the FSM procedure, I can pull those for you, but you're going to need Techstream to do anything.

Do you have any leaking shocks?
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No leaky shocks. Cycled low and high. The difference between right and left side in L and in H was about 1". In N height, the difference is still about 2". Think i need a reset? If I need a techstream, is there a bargain one off Amazon that the board recommends?
 
joesrcool said:
Alright, I have an update on the issues I was having and the easy way they all seemed to be resolved. To refresh everyone on what was done since I purchased the vehicle a month ago, I played with the height settings to see what type of sensor lift I could get and then lowered it back down to the factory recommended settings and I completed a full AHC fluid flush.

Symptoms experienced:
  1. Stuttering when raising lowering
  2. Side-to-side movement when raising lowering
  3. Vehicle would sit and drive uneven for periods at a time, unable to duplicate upon command, this would cause the steering wheel to be off-center
  4. Vehicle would not enter "LO" 9 out of 10 attempts
  5. When transitioning from "HI" to "N" vehicle would lean almost every time
  6. Vehicle would ride smooth immediately after startup, then after slowing from highway speeds, ride would be very harsh until next startup
  7. I did finally get an AHC code on the dash when trying to lower and raise back up, light went away upon restarting the vehicle
  8. Sporadic side-to-side height adjustments when sitting idle or at stoplights

I was able to borrow a Techstream cable from another local Toyota guy, so I booted it up and found the only stored code. Still not too sure why I got it, verified fluid is above max line and ensured oil pressure was within spec when raising (L to N: spec is 8MPa, actual 7.95; N to H spec is 13MPa, actual 12.31). Code was cleared and has yet to return after dozens of cycles to the system.
View attachment 3032585

Stumped as to why there were no other codes, I looked at the data table to see if anything looked "off". Here is a screenshot of my data table before conducting any adjustments. I also remembered there was a note to calibrate the Vehicle Stability Control System any time there are height-adjustments made at the sensors. The G sensors readings looked a little off, especially the Back&Forth reading. There also seemed to be a bit of side-to-side discrepancies in the height readings as well. This got me to thinking, I wonder if the truck is confused as to where its at, with the G sensor and height settings trying to fight over where to set the truck's height.
View attachment 3032589

Anyways, I thought it wouldn't hurt to conduct a calibration of the VSC system and a height adjustment calibration. I found the most level parking lot in the area and measured the vehicle height multiple times to ensure it was correct. Per the FSM, front height offset is spec'd at 101mm +/-8mm, my FL was 103 and FR was 106. Rear height offset is spec'd at 94mm +/-8mm, my RL was 94mm and RR was 90mm. I probably could have adjusted the sensors a bit more to get it a little bit closer to level, but they were within spec. I used those measurements for the height adjustment calibration and I figured the truck now knew where it was sitting at all four corners. Calibrating the VSC system was simple, just follow the instructions in the FSM. Below is the data list after adjusting and calibrating.
View attachment 3032596

After completing those two simple tasks, all of my above symptoms went away. As you can see, left to right height is much more even and the Back&Forth G sensor is zero'd out. I've cycled the system dozens of times since doing this, and everything works as it should, but even smoother and faster. I have yet to experience any of my previous symptoms since doing this, and I'm comfortable with call these issues resolved.

The one thing I'm curious about and haven't had much luck finding, is the steering angle reading. The vehicle tracks perfectly straight and the little picture in the screen shows the correct orientation of the front wheels, but it seems like this should be reading 0.
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What is the procedure for calibrating the VSC?
 
Thanks, @radman . Going to try my luck using Techstream (which I just got and still learning).

I'm in a little AHC hell right now, particularly since I rounded the 4th final accumulator just a couple of hours before sunset. PITA. So, back at it tomorrow at sunrise, plus I'll add in the bleed on the 5th accumulator and hope I can get the LX to drop into LO via the switch rather than bleeding each corner.

The steering wheel is doing the 7to2 lean and I saw the yaw sensor code in Techstream.
 
My AHC access panel came off in the car wshs. Luckily rhey found d it but the bolt is gone. Anyone know the thread pitch etc so I can replace?
 
ROMR NTX said:
My AHC access panel came off in the car wshs. Luckily rhey found d it but the bolt is gone. Anyone know the thread pitch etc so I can replace?
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it's got a 10mm head on it. If you have your engine covers off, you can grab the bolt from the battery tie-down bracket to check the threads. I'm pretty sure it's the same.
 
radman said:
correct
Click to expand...
Did the jumper reset. Started her up and the lean was reduced by .5". I slightly adjuster the sensor lift on one side and she appears to be riding level(er) but I wanted to drive around a bit before measuring. Fingers crossed this will eliminate my gangsta lean and the excessive wear I am getting on my front tires.
 
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