Auto Leveling Headlight Fix

gbhrps · December 21, 2010

For about 6 months my wife's 04 ES330 has had the Automatic Headlight Leveling warning light on the dash flash at odd times. I knew that the motors for each of the headlights were working properly, because every time we started the car, they both did their little up and down dance before coming back to level out. So the problem was elsewhere.

After some online searching for what to check, I discovered that the motors took their up/down signals from a sensor (really just a volume control switch) that is located on the rear passenger side suspension. A small metal lever attached to the rearmost suspension link, is attached to a small swing arm on the sensor, and is bolted to the upper rear sub frame. Two 10 mm nuts hold it in place, and the normal wiring harness connector sends the signal to the headlight motors as the suspension goes up and down.

Removing the one on the car showed that it had a water leak, and that internal corrosion had destroyed the contacts. Ah, the wonders of salt on Canadian roads in the winter!

Anyway, the Lexus dealer wanted $490 for the sensor. That's right, its not a misprint! You can hold the whole thing in your hand, and after you open one up, you can readily see that it couldn't possibly have cost more than $25 for Toyota to have one made.

So I bought a used one online for substantially less, and installed it myself. Easy to do with no alignment issues whatsoever. Unbolt the old one, install the new one, and problem solved. No more blinding oncoming drivers as the car bounces over uneven roads.

obsidianr · January 18, 2013

I have the exact same problem and suspect the sensor, too. I know it's been a while, but would you or anyone have the part number for the sensor? Thanks!

gbhrps · January 18, 2013

obsidianr,

That's too far back for me to still have a number. I went with the picture of the sensor that was posted in the eBay add. It matched perfectly the one from my wife's car, and the year and model were the same.

I'm sure that if you contacted a Lexus dealership and asked for the part number and its cost, they'd give it to you. It is a propritory part for Lexus. No one else will sell it. But you might find with some online searching, that for the same generation years of Toyota and Lexus cars that have the self levelling headlights, there may be several that share the same part.

For instance, many years of Toyota and Lexus vehicles all share the same power window switches and brake parts, etc. My wife's ES presently has Toyota rotors on it from the V6 Camry of the same year. Cheaper to buy than the Lexus ones, and in my case, the Toyota dealer is in town, the Lexus dealer is 70 miles away. Good Luck!

obsidianr · January 19, 2013

Is the headlamp leveling ECU the same as the sensor?

I found several ECUs on eBay. Here's one:

http://www.ebay.com/itm/05-Lexus-ES330-headlamp-leveling-ecu-computer-89960-33090-/130726113255?pt=Motors_Car_Truck_Parts_Accessories&hash=item1e6fe22fe7&vxp=mtr

Did yours look like that or different?

Thanks!

gbhrps · January 20, 2013

They are NOT the same! The part that I replaced was under the passenger rear suspension. It is a small grey plastic switch control that has a 3 inch or so long arm that sweeps through a 40 degree arc. The end of it is attached to a small rod (coat hanger diameter rod) about 3 inches long, the other end of which attaches to the A arm of the passenger rear wheel.

As the rear wheel moves up and down it pulls or pushes on the small rod, which in turn sweeps the switch arm through an arc, sending the signal to the headlight motors, via that computer box you see in the eBay ad. The switch body measures 1.5 inches by 1.5 inches by 3/4 of an inch thick and has four screws, one in each corner. It has a short two or three wire connector and attaches to the underbody of the car, above the suspension.

I can't say that this under car part is the same one that you need, or that the one pictured in the eBay ad you provided is it. All I can say is that the one I describe worked for me, simply because when I opened up my switch it was full of rusty corroded parts and obviously the culprit.

I would bet that if you contact the eBaye seller he could provide the part I describe from his parts car. But whether or not you need the one part or the other, someone will have to diagnose that first. I suggest you climb under the car and remove the switch part I described, remove the four screws and open it up carefully and check its insides. If you're comfortable with that job yourself.

If not, get a Lexus dealership to tell you what parts gone south, and then buy a used one from your eBay guy. That will be your cheapest route. Good Luck!