Rx300 Head Light Adjustment

stevekite · December 28, 2015

Question,,
my head lights on my 2004 RX300 have a self adjustment built in each time i start the car. they move up and back down then stop at the correct level when started. recently they only go up and stay up causing me to dazzle on-coming vehicles. dose anyone know why this is. As we have had a lot of rain i believe this may be a factor. sensor maybe...
thoughts please...thanks..

katabrontes · December 28, 2015

I think your idea about rain is probably right. I have the same problem with my RX350. It started after heavy rain while I was in France last year. I have asked various people about it and so far no one has come up with an idea. Sometimes the AFSA light comes on but other times it doesn't. The first thing I did was to to pull off the plug on the leveling sensor (just inside rear off side wheel) and pack it with silicone grease which seemed to fix it for a while. I was gong to replace the sensor but they are pretty expensive (about £200 as I recall) so the next plan is to take the cover off and clean the contacts (I gather its a pretty simple rheostat but you have to be careful about an internal spring when you take the cover off).

The short term fix is to switch off the ignition and then start the engine again which nearly always fixes it. Occasionally you need to do this twice.

Good luck. I would be interested what you find out about it as well.

ChrisKaye · December 28, 2015

+1 for Katabrontes post!

There is a great guide for cleaning the height sensors on here, well worth a try! If you have a multimeter, you can also test the height sensor before and after cleaning to know for sure if that is the problem...

katabrontes · December 28, 2015

Hi Chris

Found the link. As you say very helpful.

http://www.lexusownersclub.co.uk/forum/topic/54815-headlight-leveling-sensor/?hl=%2Bcleaning+%2Bafs+%2Bsensor#entry601804

WKR

Mike

ChrisKaye · December 28, 2015

Here's a pic of a height levelling sensor from the RX300 and the service manual page underneath with other useful info.

This pic came from a post on this forum, unfortunately I can never remember who (boxbrownie?) originally posted it!

PCM · December 28, 2015

FYI? http://st.club-lexus(blocked word)/files/light_373.pdf

ChrisKaye · December 28, 2015

Hi Piers,

Great find, those Ruskies are full of useful info for RX300's!

The link didn't work on my phone (I think there may be a stray character in it) but this one should be fine:

http://st.club-lexus(blocked word)/files/light_373.pdf

Ta!

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katabrontes · December 28, 2015

Thanks for the pic Chris. The service page suggests it is for the air suspension but it looks the same as the one on my RX350 which is just for the headlights. I think there is only one inside the OS rear wheel but I haven't checked the front so there may be another one there.

I have emailed for the shaft seal. What size of "O" ring is it?

Regards

Mike

katabrontes · December 28, 2015

Thanks for this useful guide Piers. It doesn't show the height levelling sensor which I have on my RX350. Is this not used on the 300?

ChrisKaye · December 28, 2015

Hi, they are the same parts on the rx300 and 350. Also there are two at the back and two for the front wheels.

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katabrontes · December 28, 2015

Is this the air suspension version? I have springs.

ChrisKaye · December 28, 2015

The sensors are dual purpose, they control the auto-levelling headlights and height (if you have air suspension)

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katabrontes · December 28, 2015

Understood Chris. I think there is only one on the rear OS suspension but I will check when I get back.

ChrisKaye · December 29, 2015

I think they are connected to the anti roll or sway bar - it threw me when I first took one off as I assumed they were attached to the struts.

The body of the units are on/near the rear axle mount with the rear diff in the middle, you then have two little drop links (like in the picture) that connect to the sway bar (iirc!)

steelgtr · August 25, 2020

On 12/28/2015 at 2:58 AM, katabrontes said:

Hi Chris

Found the link. As you say very helpful.

http://www.lexusownersclub.co.uk/forum/topic/54815-headlight-leveling-sensor/?hl=%2Bcleaning+%2Bafs+%2Bsensor#entry601804

WKR

Mike

Hi guys,

That link is dead. My 01 RX 300 doesn't self level on startup anymore but no warning light on dash. I'm US based if it matters?

thx

bob

Gliderdave · August 28, 2020

Hi guys, I have just recently had this problem and managed to sort it.

It started with a rusted broken adjuster linked to the sensor which is located on the offside rear suspension. I replaced this part from an eBay seller for £5 including delivery!. However this didn’t cure the problem entirely and after searching eBay and amazon etc I sourced a new sensor for £25 and ‘bingo’ all is now sorted for a total £30. Result!.

djgrubber · August 31, 2020

On 8/28/2020 at 9:28 AM, Gliderdave said:

Hi guys, I have just recently had this problem and managed to sort it.

It started with a rusted broken adjuster linked to the sensor which is located on the offside rear suspension. I replaced this part from an eBay seller for £5 including delivery!. However this didn’t cure the problem entirely and after searching eBay and Amazon etc I sourced a new sensor for £25 and ‘bingo’ all is now sorted for a total £30. Result!.

It is funny because I was about to write a post about this auto leveling sensor and ask you guys about a few things. You have perfect timing. Could you please advise and post links to auction/supplier from Ebay/ Amazon?

My headlights move up and down as they should, however, from time to time the autolevelling light comes on. It has been on for 3 months, then suddenly it disappeared for 2 days and now it is back again. First of all I am going to check whether the adjuster linked to the sensor is not broken /corroded. Then I am going to take the sensor out and clean it.

Now my questions are:

1. Do I need to disconnect the Battery before disconnecting the sensor?

2. Can I drive the car after I disconnect the sensor (I mean turn the ignition on etc.).

3. Can I turn on the lights or is it safer to not start the car until I plug the sensor back in?

Are there any other sensors responsible for the autolevelling? I think that my model doesn't have AFS, my lights don't move left/right, only up and down. I know that there are some actuators in the head lights, but these are probably fine since I can see the movement. Is there any sensor in the front of the car or somewhere else?

I have Techstream for Lexus on my laptop and I was wondering whether I should plug it in first and see what kind of error it is going to show. Would Techstream indicate which sensor failed or would it show a general error 'problem with autolevelling'?

Gliderdave · September 1, 2020

Hi djgrubber, I did the job without disconnecting the Battery. The sensor has a very substantial plug in assembly. I would imagine if the sensor was left unplugged then no damage would happen but the warning light would be illuminated.

It is only a headlight levelling system and not AFS. There are no other sensors controlling the headlights on my car which is an RX300 SE.

The parts I used are 48906-35010 Sensor link adjuster.

89405-48020 Sensor unit.

The link I got from eBay for a fiver and the sensor I got from amazon for £25 including free postage.

I was lucky enough to have a professional car technician check my car with a Code reader but nothing was showing.

Hope you sort it .

DaveB

djgrubber · September 4, 2020

On 9/1/2020 at 4:41 PM, Gliderdave said:

Hi djgrubber, I did the job without disconnecting the battery. The sensor has a very substantial plug in assembly. I would imagine if the sensor was left unplugged then no damage would happen but the warning light would be illuminated.

It is only a headlight levelling system and not AFS. There are no other sensors controlling the headlights on my car which is an RX300 SE.

The parts I used are 48906-35010 Sensor link adjuster.

89405-48020 Sensor unit.

The link I got from eBay for a fiver and the sensor I got from amazon for £25 including free postage.

I was lucky enough to have a professional car technician check my car with a Code reader but nothing was showing.

Hope you sort it .

DaveB

Many thanks!! This is super helpful. I also have RX300 SE. I had the car on a ramp today and it seems that I have only one sensor at the rear on the driver’s side. The whole assembly looks very corroded although the sensor link adjuster looks ok. The corrosion has probably got into the sensor.