AHC Issue... Not working at all

[TEXAS 57]

Hello,

I have a 1999 LX470. The AHC has never worked.

I have search and read countless threads on AHC problems and cannot find my problem. I am familiar with all the popular maintenance threads.

The ride comfort level selector works great as it should.

The Normal light is on.

I can turn it "OFF" with the button. The OFF light comes on.

Selecting "UP" with the button does nothing, but when selecting "DOWN" the Down Arrow light flashes.

Any ideas where I should start on this?

If I understand correctly, I don't think I can flush the system with it not functioning.

This LX has 350K on it but was dealer maintained until 300K. Visually, I feel it sits a little low in the front.

Thanks in advance.

Actually, looking at this pic next to my cranked T Bars on my LC, it doesn’t look low.

 

[128keaton]

Hey bud. No PTC codes? I know that the system does not function without the engine on and the doors shut, maybe a sensor there is messed up. Have you checked what the speed sensors are reporting with TechStream? What about the height sensors?

 

[TEXAS 57]

I do not get a check engine light or any blinking light codes I can measure. I am waiting for a different Mini VCI cable as I could not get the other one (32 bit) to work. Hopefully, this one will work and I can get some Techstream #s soon.

 

[Biga27110]

Ive had this issue when the sensors were far out of alignment. For example, if the left side was an inch higher or lower than the right it wouldnt like that.

 

[128keaton]

Ive had this issue when the sensors were far out of alignment. For example, if the left side was an inch higher or lower than the right it wouldnt like that.

I was thinking this myself, glad that this could definitely happen. OP, the tech stream software will report what the height sensors are reading. At best, they need to be adjusted and cleaned, worst I believe is replacement.

 

[Biga27110]

I was thinking this myself, glad that this could definitely happen. OP, the tech stream software will report what the height sensors are reading. At best, they need to be adjusted and cleaned, worst I believe is replacement.

I replaced mine recently I got them for cheap. I believe I bough Toyota head light sensors for camry they are the same but really cheap. Search forums.

 

[bencallaway]

How is your fluid level?

 

[TEXAS 57]

Fluid level is good and looks decent.

Thanks for the above replies about checking the Sensors. That will be first.

 

[neckbone]

I have a ‘99 as well. AHC worked perfect when I bought it, but after a couple years, it’d go down like it should, but going up, I’d have to push the up switch a few times. Finally, it wouldn’t do anything, just like yours is doing.

Bought a new switch, popped the old one out, put new one in and now works perfectly for only $130. (Should have only been $65, but I went on ebay and bought a newer switch that didn’t have the right connector. Bought the right connector from a Mud member for same price.)

I would definently start with a new switch if I were you. I’ll warn you, take yours out first and look at the connector and make sure they match. I can’t remember which is which, but one is black one is tannish. One is square, one is rectangle.

 

[neckbone]

This is the one that fit my ‘99 LX. I would imagine yours is the same. You’ll find multiples on EBay for about $60-70, or maybe someone here has one.