Check Headlight System ( 2012 RX-450h )
Thread Starter
Driver
Joined: Jan 2024
Posts: 60
Likes: 7
From: Delaware
Check Headlight System ( 2012 RX-450h )
I'm getting a Check Headlight System message on my 2012 450h. Car is new to me, I think the headlights are the triple LED version; output doesn't look like HID bulbs to me.
Headlights look new, driver's side has moisture/water inside, which is (my guess) the culprit.
Research so far says water inside headlight = corrosion of wiring connections, or, could be a a loose whatsis, or, maybe the suspension part that signals the computer about ride-height is mis-adjusted (previous owner had new lower control arms + ball joints installed - 6,000 miles ago), or, there's a bad auto-leveling motor. Have not disconnected battery to see if that will help, do know that shutting down the car makes message go away until headlights are switched on again.
Worst case, I already know I can pull the fuse powering that system, and then ignore the problem - no message will show up again, but would rather have things working properly.
Anyone with experience with this issue ?? or can point me to a DIY for removing the headlight assembly?
Headlights look new, driver's side has moisture/water inside, which is (my guess) the culprit.
Research so far says water inside headlight = corrosion of wiring connections, or, could be a a loose whatsis, or, maybe the suspension part that signals the computer about ride-height is mis-adjusted (previous owner had new lower control arms + ball joints installed - 6,000 miles ago), or, there's a bad auto-leveling motor. Have not disconnected battery to see if that will help, do know that shutting down the car makes message go away until headlights are switched on again.
Worst case, I already know I can pull the fuse powering that system, and then ignore the problem - no message will show up again, but would rather have things working properly.
Anyone with experience with this issue ?? or can point me to a DIY for removing the headlight assembly?
Last edited by Riickk; Feb 20, 2025 at 09:09 AM. Reason: spelling
CL Community Team
Joined: May 2005
Posts: 7,150
Likes: 1,711
From: VA
You have HID headlights bulbs, not LED.
The suspension headlight height sensor is on the rear suspension, not the front.
Your issues are all probably related to water in the light housing.
However some condensation inside the housing is normal as long as it evaporates during the day.
There are YouTube videos on how to remove it and it is covered in some of the links below. The HID headlamp assemblies are very expensive to replace and I would first try to seal it yourself with some heat resistant RTV silicone sealant or whatever is recommended in the linked threads.
See these related threads:
https://www.clublexus.com/forums/rx-...-moisture.html
https://www.clublexus.com/forums/rx-...e-fogging.html
https://www.clublexus.com/forums/rx-...placement.html
https://www.clublexus.com/forums/rx-...ng-system.html
https://www.clublexus.com/forums/rx-...ment-help.html
These discuss removal of the headlamp assembly.
https://www.clublexus.com/forums/rx-...eadlights.html
https://www.clublexus.com/forums/rx-...placement.html
The suspension headlight height sensor is on the rear suspension, not the front.
Your issues are all probably related to water in the light housing.
However some condensation inside the housing is normal as long as it evaporates during the day.
There are YouTube videos on how to remove it and it is covered in some of the links below. The HID headlamp assemblies are very expensive to replace and I would first try to seal it yourself with some heat resistant RTV silicone sealant or whatever is recommended in the linked threads.
See these related threads:
https://www.clublexus.com/forums/rx-...-moisture.html
https://www.clublexus.com/forums/rx-...e-fogging.html
https://www.clublexus.com/forums/rx-...placement.html
https://www.clublexus.com/forums/rx-...ng-system.html
https://www.clublexus.com/forums/rx-...ment-help.html
These discuss removal of the headlamp assembly.
https://www.clublexus.com/forums/rx-...eadlights.html
https://www.clublexus.com/forums/rx-...placement.html
Thread Starter
Driver
Joined: Jan 2024
Posts: 60
Likes: 7
From: Delaware
Thanks for the information!!
Yes, I've watched several YouTube videos on pulling the headlight assembly, as well as one on DIY opening and then resealing the headlight assembly so it's water tight. I don't want to have to do this job twice.
What's amazing, is that you can now buy new polycarbonate (?) covers for these headlights, cheap. UV damaged headlights can be disassembled, cleaned, and a new clear cover fitted. When done it looks brand new. I'm going to guess that you'll get well over 5 years out of that. Pulling the bumper will be a PITA, but worth the effort.
Yes, I've watched several YouTube videos on pulling the headlight assembly, as well as one on DIY opening and then resealing the headlight assembly so it's water tight. I don't want to have to do this job twice.
What's amazing, is that you can now buy new polycarbonate (?) covers for these headlights, cheap. UV damaged headlights can be disassembled, cleaned, and a new clear cover fitted. When done it looks brand new. I'm going to guess that you'll get well over 5 years out of that. Pulling the bumper will be a PITA, but worth the effort.
Thread Starter
Driver
Joined: Jan 2024
Posts: 60
Likes: 7
From: Delaware
I removed the plastic engine covers, and found the driver side headlight was clearly damaged at some point. Two (or more) mounting point tabs are ugly-expoxied back together. There is a small 12v motor as part of the assembly, guessing it does the auto-leveling. My very bad, should have had mechanic pull the engine covers for a good look, before buying the vehicle. Too late is much too late.
Researching, I found a company who's selling new aftermarket HID/Xenon headlamps for the 2010-11-12 RX, at an excellent price. However, their units have "AFS" - which does left/right adjusting iirc. Any way I can tell if my headlights I have also have AFS??
Researching, I found a company who's selling new aftermarket HID/Xenon headlamps for the 2010-11-12 RX, at an excellent price. However, their units have "AFS" - which does left/right adjusting iirc. Any way I can tell if my headlights I have also have AFS??
CL Community Team
Joined: May 2005
Posts: 7,150
Likes: 1,711
From: VA
If you have a 2012 with HID then you have AFS. They stopped providing AFS with the 2013 mild refresh.
To test it drive at night and when going around corners or turning the steering wheel note if the headlight beams appear to move left and right as you turn the steering wheel and car.
You could probably do this test while parked and just turning the steering wheel.
To test it drive at night and when going around corners or turning the steering wheel note if the headlight beams appear to move left and right as you turn the steering wheel and car.
You could probably do this test while parked and just turning the steering wheel.
Last edited by Clutchless; Feb 23, 2025 at 05:31 AM.
Thread Starter
Driver
Joined: Jan 2024
Posts: 60
Likes: 7
From: Delaware
Well the dream was sweet while it lasted. The company selling the new headlights got back to me and the electrical connectors are for the 350 and not for the 450h, won't work. Hooked a hair dryer using low heat, to the headlight assembly, for 40 minutes, trying to dry it out. Still getting the check headlight system message.
I have Techstream; I'm wondering if the DTC for this message (B2430) needs to be cleared for the message to go away, or will disappear after x number of miles??
I have Techstream; I'm wondering if the DTC for this message (B2430) needs to be cleared for the message to go away, or will disappear after x number of miles??
Last edited by Riickk; Feb 24, 2025 at 09:46 AM.
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Thread Starter
Driver
Joined: Jan 2024
Posts: 60
Likes: 7
From: Delaware
I'm using version 16, and though logically there would be a button, pop-up, etc. to erase a DTC... Don't see it.
~~~ Just reviewed a manual for version 18, erasure ability is there. Need to look at live screen again.
~~~ Just reviewed a manual for version 18, erasure ability is there. Need to look at live screen again.
Thread Starter
Driver
Joined: Jan 2024
Posts: 60
Likes: 7
From: Delaware
Erased the B2430 code, twice, but a minute or so after headlights are turned on, the code returns.
I know the leveling system is working, and so is the afs system.
What's left? Corrosion at the electrical connectors so that the computer sees too much resistance at one terminal or another?
I know the leveling system is working, and so is the afs system.
What's left? Corrosion at the electrical connectors so that the computer sees too much resistance at one terminal or another?
CL Community Team
Joined: May 2005
Posts: 7,150
Likes: 1,711
From: VA
Corrosion is the most likely source for the code.
Did you check and clean all the wiring connections to the bulbs and the ballasts? Make sure there is no corrosion.
If you have the original bulbs, try replacing them as maybe one is going bad, and they do get dimmer over time, so you will improve night vision with new bulbs. It is a D4S HID bulb and good brands are Osram, Philips, Toshiba, Hella which are available online at places such as Amazon. Do not touch the new bulbs with bare skin as the oils create hot spots that make the bulb burn out sooner.
Did you check and clean all the wiring connections to the bulbs and the ballasts? Make sure there is no corrosion.
If you have the original bulbs, try replacing them as maybe one is going bad, and they do get dimmer over time, so you will improve night vision with new bulbs. It is a D4S HID bulb and good brands are Osram, Philips, Toshiba, Hella which are available online at places such as Amazon. Do not touch the new bulbs with bare skin as the oils create hot spots that make the bulb burn out sooner.
CL Community Team
Joined: Apr 2001
Posts: 16,533
Likes: 1,379
From: Austin, TX
Erased the B2430 code, twice, but a minute or so after headlights are turned on, the code returns.
I know the leveling system is working, and so is the afs system.
What's left? Corrosion at the electrical connectors so that the computer sees too much resistance at one terminal or another?
I know the leveling system is working, and so is the afs system.
What's left? Corrosion at the electrical connectors so that the computer sees too much resistance at one terminal or another?
Salim
Thread Starter
Driver
Joined: Jan 2024
Posts: 60
Likes: 7
From: Delaware
I'd rather work on it myself, but I'm stumped at this point. The error code "meaning" is too broad. Of course the Techstream version I have won't communicate back to Toyota servers. ?? But, does this matter ?? If I take the vehicle into Toyota or Lexus Dealer, for diagnosis, will they get a more precise picture of what the problem is, or just the same error code I already have. In the same vein, if I go to the TIS website can I download the repair manual, or just use the Manual during the subscription period? (( The last time I tried using that site was so long ago, I may have been using most modern tech available to consumers at that time.... a 4800 or 14.4K modem.))
Last edited by Riickk; Feb 27, 2025 at 05:26 PM.
CL Community Team
Joined: Apr 2001
Posts: 16,533
Likes: 1,379
From: Austin, TX
I'd rather work on it myself, but I'm stumped at this point. The error code "meaning" is too broad. Of course the Techstream version I have won't communicate back to Toyota servers. ?? But, does this matter ?? If I take the vehicle into Toyota or Lexus Dealer, for diagnosis, will they get a more precise picture of what the problem is, or just the same error code I already have. In the same vein, if I go to the TIS website can I download the repair manual, or just use the Manual during the subscription period? (( The last time I tried using that site was so long ago, I may have been using most modern tech available to consumers at that time.... a 4800 or 14.4K modem.))
Incidentally I am hearing that techstream may soon be replaced with a more modern version.
Salim