After towing LX 2500 miles AHC won’t go into high. (1 Viewer)

[Sventvkg]

It seems to go into high, but then comes back down into low. I know I have needed to change the fluid and I’m going to get to it very soon, but is there any other reason you can think of that it won’t go into high? It also doesn’t feel the same. It’s more spongy like the comfort setting Isn’t responding either. Did I mess up a sensor? Any insight appreciate it thank you.

EDIT:
I just realized I have a hitch cargo rack on the back with probably 300 pounds worth of stuff, a generator and a couple bins. Could that have something to do with the front going up in high but then coming back down? The back doesn’t move.

 

[GTV]

Flush fluid. Get techstream on it. Correct your pressures.

 

[Kabanstva]

AHC problems. Sounds all to familiar.

 

[Sventvkg]

AHC problems. Sounds all to familiar.

I honestly think the rear won’t go up because of the cargo. I have on the back and I didn’t even think of that when I posted this that said. If I do have eight HC problems, I will be going with a lift and a standard suspension

 

[Kabanstva]

I honestly think the rear won’t go up because of the cargo. I have on the back and I didn’t even think of that when I posted this that said. If I do have eight HC problems, I will be going with a lift and a standard suspension

I also couldn’t control the ride height on mine every time I packed for a big trip and took hundreds of pounds of gear. Messing with suspension pressures just wasn’t something I was interested in doing. A couple times it left me in low mode in the middle of rocks and pissed me off. AHC is gone now for good. I don’t miss it at all.

 

[Sventvkg]

I also couldn’t control the ride height on mine every time I packed for a big trip and took hundreds of pounds of gear. Messing with suspension pressures just wasn’t something I was interested in doing. A couple times it left me in low mode in the middle of rocks and pissed me off. AHC is gone now for good. I don’t miss it at all.

Yeah, although I love the ride, it’s definitely on my list for a lift and a more off-road suspension.

 

[GTV]

I honestly think the rear won’t go up because of the cargo. I have on the back and I didn’t even think of that when I posted this that said. If I do have eight HC problems, I will be going with a lift and a standard suspension

If your pressures were in spec and it wasn't overloaded way beyond design it would go up no problem.

The average person doesn't maintain the system for a decade or two, something like this happens and the blame is placed on AHC when it's actually just neglect.

 

[Kabanstva]

If your pressures were in spec and it wasn't overloaded way beyond design it would go up no problem.

The average person doesn't maintain the system for a decade or two, something like this happens and the blame is placed on AHC when it's actually just neglect.

What do you consider maintain? My LX had the fluid changed several times throughout its life. I bought it with 116k miles, from the original owner. My brother was their service adviser at Lexus since day one. Every recommended service was always done. What exactly do you consider neglect? Spending thousands replacing globes and all that other crap in the system? Edit: vehicle was only 8-9 years old when I bought it so far from old by Toyota standards…and remember the whole 25 year cycle they claim with Land Cruisers….

 

[OEMGUY0720]

300 pounds is a lot of weight for AHC, I think this the reason why it’s not coming up to High.

EDIT:
I just realized I have a hitch cargo rack on the back with probably 300 pounds worth of stuff, a generator and a couple bins. Could that have something to do with the front going up in high but then coming back down? The back doesn’t move.

I can relate because this happened to me once.

 

[Kabanstva]

300 pounds is a lot of weight for AHC, I think this the reason why it’s not coming up to High.

I can relate because this happened to me once.

That’s crazy lol. That’s literally just slightly above average weight of an adult male in America. So much for heavy duty suspension.

 

[OEMGUY0720]

That’s crazy lol. That’s literally just slightly above average weight of an adult male in America. So much for heavy duty suspension.

Agree. We were driving back from San Diego to Las Vegas and had a lot of stuff in the back. Had to pull over in a gas station, turn off the engine, unload a few stuff, start up the LX and the rear went back up to Neutral/Normal height. While the engine was running I loaded all the stuff I unloaded and it didn’t squat again. I hated it because the headlights were aimed high and was blinding the cars infront of me so I had to try out something. Surprisingly that worked. Next order of business is King HD Springs.

 

[Kabanstva]

Agree. We were driving back from San Diego to Las Vegas and had a lot of stuff in the back. Had to pull over in a gas station, turn off the engine, unload a few stuff, start up the LX and the rear went back up to Neutral/Normal height. While the engine was running I loaded all the stuff I unloaded and it didn’t squat again. I hated it because the headlights were aimed high and was blinding the cars infront of me so I had to try out something. Hopefully that worked. Next order of business is King HD Springs.

Sounds similar to me. AHC never left me stranded but that’s probably because I am always proactive whenever I do long distance travel. I remember this one time in Colorado we are driving at highway speeds between Silverton and Grand Junction and out of the blue the vehicle starts driving like absolute ass….imagine no suspension damping at all. Pull over , pop the hood and see the AHC fluid reservoir is low, next to empty on fluid. I had spare fluid with me in cans, filled it and went about our day, no issues since then….BUT it makes you wonder wtf that was all about, no leaks anywhere underneath the car, no trail damage to any lines, etc. That was the time I lost all trust in that system and decided to have it removed.

 

[Sventvkg]

If your pressures were in spec and it wasn't overloaded way beyond design it would go up no problem.

The average person doesn't maintain the system for a decade or two, something like this happens and the blame is placed on AHC when it's actually just neglect.

I can see that. As I stated, I’m due to change my fluid and although I purchased techstream I wasn’t able to get it working so it’s on the list.

Definitely LX project time. Last year and a half I was building a bus conversion to live in and just towed the LX out to Utah from FL.

 

[Sventvkg]

Sounds similar to me. AHC never left me stranded but that’s probably because I am always proactive whenever I do long distance travel. I remember this one time in Colorado we are driving at highway speeds between Silverton and Grand Junction and out of the blue the vehicle starts driving like absolute ass….imagine no suspension damping at all. Pull over , pop the hood and see the AHC fluid reservoir is low, next to empty on fluid. I had spare fluid with me in cans, filled it and went about our day, no issues since then….BUT it makes you wonder wtf that was all about, no leaks anywhere underneath the car, no trail damage to any lines, etc. That was the time I lost all trust in that system and decided to have it removed.

Wow..that’s scary. The only extra fluid I have was the can I bought to change the fluid. Guess I need to find more!

 

[OEMGUY0720]

Sounds similar to me. AHC never left me stranded but that’s probably because I am always proactive whenever I do long distance travel. I remember this one time in Colorado we are driving at highway speeds between Silverton and Grand Junction and out of the blue the vehicle starts driving like absolute ass….imagine no suspension damping at all. Pull over , pop the hood and see the AHC fluid reservoir is low, next to empty on fluid. I had spare fluid with me in cans, filled it and went about our day, no issues since then….BUT it makes you wonder wtf that was all about, no leaks anywhere underneath the car, no trail damage to any lines, etc. That was the time I lost all trust in that system and decided to have it removed.

What ahc fluid is low and there’s no leak? Now that’s weird. Luckily I haven’t had that experience yet. I think that’s the major trade off of an LX to an LC - it’s load carrying capacity vs a plush ride (factory to factory comparison). Good thing we have options like LC-spec and aftermarket torsion bars, same as rear coil springs.

 

[GTV]

What do you consider maintain? My LX had the fluid changed several times throughout its life. I bought it with 116k miles, from the original owner. My brother was their service adviser at Lexus since day one. Every recommended service was always done. What exactly do you consider neglect? Spending thousands replacing globes and all that other crap in the system? Edit: vehicle was only 8-9 years old when I bought it so far from old by Toyota standards…and remember the whole 25 year cycle they claim with Land Cruisers….

Under normal circumstances, fluid changes and pressure adjusting for the first 10-15 years would suffice. It sounds like you had bad luck with your AHC and your general mood towards this platform seems to be souring as of late.

 

[GTV]

That’s crazy lol. That’s literally just slightly above average weight of an adult male in America. So much for heavy duty suspension.

300lbs hanging off the rear bumper is a lot for a system that hasn't been properly maintained.

 

[Kabanstva]

300lbs hanging off the rear bumper is a lot for a system that hasn't been properly maintained.

Why do you keep saying it wasn’t properly maintained? It functioned flawlessly under normal conditions and city driving. All settings worked, went up and down without skipping a beat, damping settings all worked as they should. If it was truly heavy duty people wouldn’t be swapping out springs and messing around with cranking torsion bars.

This was a stock weight vehicle, no aftermarket bumpers, no winch, no sleeping/drawer platforms in the trunk, literally the only mods were aluminum skids and sliders….but they proved to be too much to haul three adults and some camping gear. Far from an overbuilt suspension system. I’m not a hater but it’s laughable at how much praise AHC gets around here.

 

[Jerzywerzy5]

Why do you keep saying it wasn’t properly maintained? It functioned flawlessly under normal conditions and city driving. All settings worked, went up and down without skipping a beat, damping settings all worked as they should. If it was truly heavy duty people wouldn’t be swapping out springs and messing around with cranking torsion bars.

This was a stock weight vehicle, no aftermarket bumpers, no winch, no sleeping/drawer platforms in the trunk, literally the only mods were aluminum skids and sliders….but they proved to be too much to haul three adults and some camping gear. Far from an overbuilt suspension system. I’m not a hater but it’s laughable at how much praise AHC gets around here.

Well, I guess some of us have had better luck with it. It certainly accomplishes what many owners are looking for.

The LX is only rated for about 1200 pounds of cargo and people so 300 hanging off the rear is a good chunk of that.

 

[GTV]

Why do you keep saying it wasn’t properly maintained? It functioned flawlessly under normal conditions and city driving. All settings worked, went up and down without skipping a beat, damping settings all worked as they should. If it was truly heavy duty people wouldn’t be swapping out springs and messing around with cranking torsion bars.

This was a stock weight vehicle, no aftermarket bumpers, no winch, no sleeping/drawer platforms in the trunk, literally the only mods were aluminum skids and sliders….but they proved to be too much to haul three adults and some camping gear. Far from an overbuilt suspension system. I’m not a hater but it’s laughable at how much praise AHC gets around here.

Was it you that said they had 300lbs hanging off the rear bumper or was it @Sventvkg?

Just because it's "heavy duty" doesn't mean that you can neglect it, hang a bunch of weight off the rear bumper and expect to get away with it. You don't like AHC, that's fine. Neither did I until I learned how it works and how to maintain it.