AHB and LDA not working when cold.

[ToreOe]

One of the features in the IS300h that I didn't know i couldn't live without until I got it, is the AHB - Auto High Beam.

However, some mornings I have noticed that it fails to dip for oncoming traffic - usually when the temperature is around freezing.  It does switch between low and high beam based on how dark it is, but fails to recognize other car's lights until they are really close.  Additionally, I noticed that the LDA (Lane Departure Alert) did not detect the side and lane lines on the road.

So, what could cause this?  The sensor for AHB and LDA is a camera.  I decided to stop and take a look at it once it was not operating properly, and this is what I found:

Inside of windshield is covered in dew/mist in front of the camera.  Nothing on the rest of the windshield, and I do my best to keep the car dry inside...

I have notified my Lexus dealer of this problem.  Apparently, Toyota is having the same problems on the Avensis and Auris and have come up with a fix for it that involves installing a heater element in there with the camera.  But no fix for the IS.

While I wait for a fix from Lexus, I have simply put a small bag of Silicagel inside the cover for the AHB/LDA sensor.  The cover is easy to remove and replace, it literally took me a few minutes.  So far it seems to do the job - no more angry gestures from oncoming drivers.

 

-Tore

 

[Tash123]

That's poor...

Seems fairly dangerous as well particularly if you become reliant on the LDA system

Mine doesn't have these features

[royoftherovers]

Very interesting.It makes one wonder how much "real world "testing is carried out by manufacturers.

 

Regards

 

John

[steve2006]

That does look like a poor design, the camera either needs to be hermetically sealed or heated to prevent the problem, how come Toyota have a solution for their vehicles but not Lexus, I wouldn't be surprised if the system is the same but being Lexus it may need to be ECU controlled :)

I can see the headline now "Lexus driver charged after flashing other motorists"

I have the auto headlight system on my LS400 but tend not to use it, as you enter a dual lane tunnel in lane 2 the headlights come on, the 38 tonne lorry thinks you've flashed him out. Err no thanks.

[ganzoom]

On 20/03/2016 at 11:04 AM, ToreOe said:

One of the features in the IS300h that I didn't know i couldn't live without until I got it, is the AHB - Auto High Beam.

However, some mornings I have noticed that it fails to dip for oncoming traffic - usually when the temperature is around freezing.  It does switch between low and high beam based on how dark it is, but fails to recognize other car's lights until they are really close.  Additionally, I noticed that the LDA (Lane Departure Alert) did not detect the side and lane lines on the road.

So, what could cause this?  The sensor for AHB and LDA is a camera.  I decided to stop and take a look at it once it was not operating properly, and this is what I found:

Inside of windshield is covered in dew/mist in front of the camera.  Nothing on the rest of the windshield, and I do my best to keep the car dry inside...

I have notified my Lexus dealer of this problem.  Apparently, Toyota is having the same problems on the Avensis and Auris and have come up with a fix for it that involves installing a heater element in there with the camera.  But no fix for the IS.

While I wait for a fix from Lexus, I have simply put a small bag of Silicagel inside the cover for the AHB/LDA sensor.  The cover is easy to remove and replace, it literally took me a few minutes.  So far it seems to do the job - no more angry gestures from oncoming drivers.

 

-Tore

 

 

The auto-head lights option and adaptive cruise control stays on all the time in our IS300H. The only time it gets confused is in heavy fog, when the high beam reflects back on it self or the lights from other cars aren't as strong as normal. I've never seen the camera sensor fog up like that, if your car is still in warranty take it back to Lexus, something isn't right there with the seal.

Land departure warning I've turned off, it's funny to watch the car can 'see' where the lanes are but annoying that it cannot steer it self to keep in lane  - So it's a bit pointless.

 

[ToreOe]

The car has been to Lexus for this issue already.  They have confirmed that nothing is out of spec on my car, but it has the same construction as the Toyota Avensis and Auris and they admit the IS has the same design flaw.  Unfortunately, it seems to take long from admitting a design flaw to providing a solution, as we saw on the rear suspension vibration issue...

The camera housing is not sealed against the windscreen, so moist air will inevitably enter.  For the issue to appear it takes special conditions, though.  I only see it when I leave home in relative high temperature and humidity, and drive into an area with significantly lower temperature.  As I do on my way to work each day...

-Tore

[200h]

its not a feature i have ,could you leave the cover off the camera and let the aircon

keep the lens condensation free

[200h]

its not a feature i have ,could you leave the cover off the camera and let the aircon

keep the lens condensation free

[ToreOe]

57 minutes ago, 200h said:

its not a feature i have ,could you leave the cover off the camera and let the aircon

keep the lens condensation free

It might help, but it would look... ugly.  The cover hides not only the camera sensor, but several wire looms too.

The bag of silicagel seems to be working well, though.

-Tore