Flushed AHC but still having issues (1 Viewer)

[gryfon19]

Thanks to the wonderful information shared here over the years, I successfully flushed and replaced AHC fluid that was probably original (165k miles). Unfortunately, I'm still running into issues with the AHC and not sure how to isolate what to address next.

Prior to the flush, the vehicle rarely if ever responded immediately to pressing Hi - N - Lo. If it did adjust it typically happened once I was driving. Currently, I'm not certain but I believe the rear wheels respond in a similar fashion but the front don't. They appear to be stuck in Hi, and when the rear wheels are also in the Hi position the dash still shows N. The ride mostly sucks.

I thought maybe the front globes needed to be replaced given they don't seem to move (and certainly at least not on command), but it also seems like the vehicle doesn't really know what height the wheels are at. Despite being high in both the front and back the dash shows 'N.' Which makes me wonder about the height sensors.

2004 Lexus LX470

 

[YotaWagon]

When you press the button to go into low or high, does it blink that it's trying? I remember reading there are certain circumstances that it will not respond (like if any door is open, it will not move at all), but I don't remember exactly. I've noticed that if I come to a stop before the system is finished then it will not finish until I drive a little more.

If your vehicle has the stink bug look, and the rear is always in the high position, then it's probably a rear sensor issue. Is the dash flashing "off" for AHC? When my sensor went bad, the rear sat really high like you're describing but the system also knew something was wrong and was flashing "off" on the dashboard. Perhaps your rear height sensor just needs to be adjusted? Is this a recent problem, or a new vehicle to you and you're trying to sort it out? btw if the rear is stuck in high, the ride is going to suck.

edit: Have you done the graduation test to see how many graduations on the fluid reservoir you have?

 

[kwon-offroad]

This is futile if you don't have pressure readings prior to replacing fluid and after. A BT OBDII reader is the single most important purchase - and relatively cheap - you can make to help you through troubleshooting and maintenance.

 

[gryfon19]

When you press the button to go into low or high, does it blink that it's trying? I remember reading there are certain circumstances that it will not respond (like if any door is open, it will not move at all), but I don't remember exactly. I've noticed that if I come to a stop before the system is finished then it will not finish until I drive a little more.

If your vehicle has the stink bug look, and the rear is always in the high position, then it's probably a rear sensor issue. Is the dash flashing "off" for AHC? When my sensor went bad, the rear sat really high like you're describing but the system also knew something was wrong and was flashing "off" on the dashboard. Perhaps your rear height sensor just needs to be adjusted? Is this a recent problem, or a new vehicle to you and you're trying to sort it out? btw if the rear is stuck in high, the ride is going to suck.

edit: Have you done the graduation test to see how many graduations on the fluid reservoir you have?

Good question - the dash light blinks when I try to switch to Hi or Lo and hasn't shown OFF ever. I bought the vehicle ~2 years ago and while it would occasionally move between Hi and Lo without my touching anything, it's only been in the last month or two that it starting behaving this way. I flushed the AHC fluid a few days ago over the weekend.