AHC tips? (1 Viewer)

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I'm going through the LX owners manual, and I'm left wanting more in regards to the automatic height control. Does anyone have tips on the best way to use this for normal, highway, offroad, and towing conditions?

It seems that if left in automatic, the AHC is a bit restrictive, but you can cheat by setting the height where you want, and then turning the system off.

What are the tricks to getting the most out of the auto height and variable damping systems?

I hope this isn't a duplicatoin of an earlier thread. I did look....

T.
 
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The AHC always ends up at Normal height for highway speeds. It moves off low at about 9 mph and off high at about 20 mph. The off button is good for setting the height when doing service, jacking it up, changing tires, etc.

I have played with the variable damping some, but Comfort seems to work well in practically all conditions. I have used the 3rd setting with a full load on mountain roads with good results - but still preferred the Comfort (2) setting on the highway.
 
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I like the way my LC handles on the 3rd setting personally.. I use the second setting when the road is very bumpy etc.. Keep in mind that my lc is a lot heavier than stock.. when it was stock, 2nd setting was good for daily driving i guess.. I use the 4th setting on road when the lc is fully loaded, I have the water tank full or the highway is curvy.. for my off-road use, the 4th setting is the only way to go..

I would read the section on towing in the owners manual as it explains what you have to do exactly and when to turn the AHC off, on, etc. I am assuming that you guys have the same manuals we get here :)
 
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LXPearl said:
The AHC always ends up at Normal height for highway speeds. It moves off low at about 9 mph and off high at about 20 mph. The off button is good for setting the height when doing service, jacking it up, changing tires, etc.

I have played with the variable damping some, but Comfort seems to work well in practically all conditions. I have used the 3rd setting with a full load on mountain roads with good results - but still preferred the Comfort (2) setting on the highway.

So if I want to work on the car (everything put the AHC, of course), I start up the engine, put the AHC on high (or put the t-case into low and put the AHC on high for extra height), then when I turn off the ignition, the vehicle will stay high or will it revert to low? I thought the manual said it would only stay in low when the vehicle isn't moving, but it didn't say it would stay in high after the ignition is turned off.
 
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There's no way I would take this chance. Even if it does stay up when the ignition is off, make sure you use jack stands. I would hate to read that you're dead because the AHC dropped and smooshed you into the driveway. It would be nice to not have to pull out the jack and jackstands, but not worth the risk.
 

hoser

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Jim_Chow said:
So if I want to work on the car (everything put the AHC, of course), I start up the engine, put the AHC on high (or put the t-case into low and put the AHC on high for extra height), then when I turn off the ignition, the vehicle will stay high or will it revert to low?
It will stay in HI if you turn off the ignition. Yeah, if you want to work on it, still throw jackstands under it.
 
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Yes, I put the AHC on high, lock it in place, and change oil, lube the propeller shaft, etc. I have never tested it to see how long it will stay up, but it does well for a couple hours when working on it.

As with using a car jack, jack stands are always highly recommended, if not specified.
 
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Since this has been revived, here are a few of my observations after about two weeks of use:

1) I orignially assumed that I could put this in low for long high speed freeway driving, reducing the chances of rollover. You can't do this.

2) The comfort setting is good for most driving, but you get sloppier cornering, and you get an awkward response when hitting dips or other iregularities. You can feel the suspension automatically tighten up mid-movement. As Lexus states, the second setting seems to be a better compromise if you are never going to touch it. If you actively control it, use the 2nd setting on most surface streets, 3rd setting if driving agressively or doing a lot of cornering, the tight setting for offroad and towing, and the comfort setting on the highway.

3) It IS pretty cool putting the vehicle into high just before parking, and then putting it in low when you come to a stop. People are fairly surprised and impressed.
 
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When I first took delivery of my 06 LX I immediatly felt the difference of the ride compared to my 03 GX. The GX would bottom out on dips whearas the LX won't.

The LX also seem to float over bumps which to me seems very unnatural. At first I though that the suspension was underdamped, then I found feature on the new vehicle feature section for the 98 LX470 when it first came out. I was pleasantly surprised of the technology on these beast. Now it all make sense to me.
 
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Aren't there actually two "layers" to the AHC, one being vehicle height control (activated by the "L", "N", or "H" settings) and the other being shock absorber damping factor (comfort to sport setting)? So if I turn the ignition on and set it to high, will it raise high enough to get jackstands underneath the frame rails w/o having to use a floor jack?
 
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Yep, two distinct controls.

Once control lets you select L, N, or H heights, and there is also an automatic XH that is selected when you select H and the transfer case is set to Low Range.

The second control lets you choose 4 different levels of dampning, changing the ride from soft to firm. I originally had a bit of contempt for the soft setting, but have to admit that I find myself using it more than the other settings.
 
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CivicFerio, where did you get that writeup on the semi-active suspension control theory elements? Pretty cool. You said it came out in reference to the '98 LX470?

Definitely, I can feel the semi-active stuff working on my '99 LX. I like it. Usually leave the setting to 2 ("mid"), except when negotiating occasional high speed cornering situations which are aided by setting to 3, or on rough straight & level roads which are better absorbed by "comfort". I have towed 3000lb trailer and simply left it at 2 setting, no problem - the AHC and auto-leveling function work great for trailering.
 
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I noticed there's a sticker on the side of the center console that says to turn the AHC "off" when jacking up the vehicle, so I guess there's one answer. I left it set to "N" when I parked in the garage today (AHC switch is still on). It seems to still be at the same height.
 
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tech_dog said:
Once control lets you select L, N, or H heights, and there is also an automatic XH that is selected when you select H and the transfer case is set to Low Range.

I tried this last night, but the vehicle does not seem to go higher when I have it in H and put it in Low Range. Is there anything else that is required to get the vehicle in XH, like A-TRAC active or so?

Just curious.
 
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white_lx said:
I tried this last night, but the vehicle does not seem to go higher when I have it in H and put it in Low Range. Is there anything else that is required to get the vehicle in XH, like A-TRAC active or so?

Just curious.

Your doors must be closed and you can't have your foot on the brake for more than 5 sec. continously (so roll slowly or brake-release-brake). You also need to be going < 30km/hr in 4wd hi or 50km/hr for 4wd low.
 

uHu

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white_lx said:
I tried this last night, but the vehicle does not seem to go higher when I have it in H and put it in Low Range. Is there anything else that is required to get the vehicle in XH, like A-TRAC active or so?
Remember from the handbook something about only on an un-even surface, meaning that XH would be active only in an Off-road situation.
 
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Jim_Chow said:
Your doors must be closed and you can't have your foot on the brake for more than 5 sec. continously (so roll slowly or brake-release-brake). You also need to be going < 30km/hr in 4wd hi or 50km/hr for 4wd low.

I had it in Park and Neutral for at least a minute. I did not see it go up. If Uhu is right, how can this be tested? Do I drive over a bumpy section and will it stay up after that? I'm just curious what the extra clearance is.
 
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white_lx said:
I had it in Park and Neutral for at least a minute. I did not see it go up. If Uhu is right, how can this be tested? Do I drive over a bumpy section and will it stay up after that? I'm just curious what the extra clearance is.

I'd try to roll forwards slowly while pushing the button. The height status should also be indicated on the dash (L, N, or H). In 4wd hi, the difference between each setting is like 1.5-2". I'm not sure how to ensure it's in extra-high mode in 4wd low. Not sure if there are sensors underneath the vehicle that detect objects? So far, I give the AHC a thumbs up.
 

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