'06-'07 LED brake light illumination issue, anyone see this before?

[aging fleet]

I didn't find anything when I searched the 100 and 120 forums so this may be a new one.

While getting ready to back out of my garage, I had my foot on the brake and noticed in my peripheral the bright red light from my brake lights reflecting off the wall suddenly turned off (but my foot was still on the brake). I pumped the brakes a few times and still no bright light.

At one of my stops on the way into work, I backed up to a wall of windows to see what was going on in the reflection. My lights all appear to work, my brake lights just don't go into high intensity mode. With the lights off, you see all the brake lights come on, just not brightly. With the lights on, you see a flicker as you tap the brake, but, because the intensity is the same as the standard tail lights, you really can't tell the brake lights are coming on. Thankfully the third taillight is still works, though also at a lower intensity.

If I put my Captain Obvious hat on, it appears there is a switch somewhere in the system that not only tells the brake lights to turn on, but also to be brighter than normal. That thing is apparently broken.

Anyone run into this before?

Random info for background: '06 LC w/ 102k, currently 18*F outside, no rain or moisture recently that would lead me to believe there is a moisture issue, when the LC is not being driven it's in a covered parking garage at work or in my garage.

 

[NorCalFJ100]

I have a 2006 as well. I just purchased last week I came across your post, I am curious if you find an answer. I am looking for a similar question, my brake lights only seem to work on the part of the light that is on the body. The brake lights do not come on that are located on the tailgate. When I turn on the headlights, they come on...just no brake lights. I am wondering if we both may come across a similar culprit.

 

[aging fleet]

Congrats on the new truck. I just saw your thread too, for a moment I thought you were having a similar issue. Sounds like yours tails are working fine though.

I've had a crazy busy weekend so I haven't had a chance to look mine over yet, hopefully I'll get some time today. I'll definitely report back once I've got it figured out.

 

[S.CarolinaFZJ80]

Might be a bad ground? Or maybe a dirty brake switch in your pedal assembly? Or bad connection at the light?

I have an '07 LX but have not had the same issue yet.

Maybe someone with an electrical diagram can post up the schematic.

It the meanwhile you could probably remove the brake pedal switch and use a multi-meter to check the switch. It might be as easy as spraying some electrical contact cleaner in the switch?
Also, check for corroded grounds under the driver kick panel and connection at the hatch/spoiler LED.

 

[aging fleet]

I finally got a few hours to screw around with this so I spent some time looking over the EWD and body electrical portions of the FSM, grabbed a multimeter and an IPA and headed for the garage.

What I did...

• tested fuse 44 visually and with the multimeter - fuse was fine
• pulled the left and right side tail lights and tested ground at the plug - passed with flying colors, almost no resistance to earth
• unplugged the brake light switch and tested continuity at pins 1 & 2 (pedal depressed) and 3 & 4 (pedal released) - switch is working

After testing the fuse and ground at the tails, I tested the brakes just to see if unplugging and plugging them in made a difference. It hadn't so after doing the continuity test with the brake light switch, I decided it was time to wrap up for the night. I cleaned up and started the truck to do another quick test, after the dash lit up like a Christmas tree, I realized I forgot to plug the switch back in. Turned truck off, plugged switch back in, turned truck back on. Tested brake lights, and they work.

I'm under no illusion that I actually fixed something. Maybe one of the pins was loose on the back of plug to the brake light switch, maybe my truck is just screwing with me and they'll be broken again by the morning, or maybe something else I touched in the kick panel had an affect.
Not sure, but hopefully the Toyota gods are happy for the short term.

I'll continue to update this if the problem persists, maybe it will help someone else down the road.

 

[aging fleet]

Update...

Of course the brake lights stopped working the morning after my last post so I thought about it a bit more, looked over the wiring diagram again and came to the conclusion that the brake light switch was the most probable cause despite passing the resistance test outlined in the FSM.

Last night I messed with the switch for a few minutes, unplugging it and plugging it back in. I could get the brake lights to work intermittently but they would stop after a few pumps of the brake or if I turned the lights on. Pretty weird stuff. So, I headed to the dealership today and paid full MSRP ($62) for a new switch because I felt I was pressing my luck driving the car the way it was. NAPA did have one available for $31, but I haven't had great luck with non-OEM parts.

Happy to report it only took a few minutes to swap out the switch and the brake lights are working great. I attached a few photos that may help someone down the road. This is an easy job if you have a 14mm crow foot, I didn't so I bent a 14mm wrench and was able to get the job done.

Have a great weekend everyone!

 

[NorCalFJ100]

Great post! Thanks for the information. This is a good one to remember if there's an issue like this down the road! Glad you got it fixed

 

[r3run33]

thanks for posting fix hey where is the switch located in engine bay looked at your pic several times but could not place it.

 

[CharlieS]

Inside the car under the dash near the brake pedal, not in the engine bay.

 

[aging fleet]

thanks for posting fix hey where is the switch located in engine bay looked at your pic several times but could not place it.

As CharlieS mentioned, it sits under the dash and it's a challenge to get to. The universal joint in the third picture is where your steering column passes through the firewall.