TRD Sport parking lights

So I have halogen headlights but my parking lights are the LED type.
Here’s what I noticed recently;
When I used to turn them on (parking lights only) they would be on at a dimmer level. When I’d disengage the parking brake the parking lights would get much brighter.

Now, when I do this they remain at the dimmer level and never change intensity.

I looked through the owners manual and nothing there. Wonder if any of you have experienced this?

 

Are you talking about the DRL? The L shaped white light? It has a separate fuse under the hood, I'd start there. Also, are the low beams on when you are checking? You have AUTO headlights I assume.

 

Not the DRL. Yes, the L shaped LED parking lights.

Headlights are off when checking. And I do have the auto setting, but don’t use it.

I’ll definitely check for a fuse.

 

Those white lights are the DRL. They should come on full brightness if the AUTO is selected and its light outside, or if parking lights are selected. Both are dependent on the parking brake being off. Then, when the low beams come on, they dim to about 50% or so. That is why I think a fuse is most likely it. The dim function is driven by the parking lights, so they would turn on with just parking lights, but not full brightness. If you need to, there is a plug toward the bottom of the headlight with a green, a white/black, and a pink or blue wire. The green on that plug is the DRL, so you can check it for 12V

 

DRL’s gotcha. I’ll check the fuse 1st. Hopefully that’s the culprit. Don’t know why it would have blown? They still come on but only at the 50% level.
Thanks.

 

As puppypunter said. Those are a dual brightness that serve as DRL and parking light. During daytime, if lights are set to auto, it will go from off to full brightness when you start the truck and release the parking brake. When low beams or running lamps are selected (or night time sets in while in auto), the Ls will dim down to be parking lamps. If low beam is disabled by the sun coming out again, headlights will turn off and they will go back to full brightness as DRL, unless you flip the stalk to DRL off at which point everything will be off.

 

Another scenario to be aware of: if you are in running lamps mode, and you turn on the fogs, the parking lamps will be at half brightness. If you select parking lamps with fogs off, parking lamps should be full intensity (like DRL, except the amber side markers will also be on bc running lamp mode). When low beams are selected, the Ls will always be 50% brightness.

Didja recently turn on fogs?

 

Yeah, that 50% is a different circuit. I am not sure why they would have blown either, but if you replace the fuse and it blows again, then I'd look further into it.

 

I did not know that. I have neither factory AUTO nor fog lights though. Thanks for teaching me something

 

Yeah, I learned it one day at my favorite chick fil a, facing the window while parking….flipped my lights to running lamp so as to not make the folks inside uncomfortable. For whatever reason, did not have my fogs enabled that time (usually do). Noticed the DRL/parking lamp was full brightness despite night time. Side markers on. Turned on the fogs and then they intensity reduced to half.

Not sure why Toyota did it that way honestly - the DRL is bright enough to be relatively uncomfortable to look at at night time. Not sure why having fogs off means the strip needs to kick up to full brightness. But anywho, it is good information to know.

 

Thanks for all that info.

I was just checking them with only the Ls selected on the switch. Nothing else. No fogs, no auto. They remain at 50% output.

Thankfully she’s still under factory warranty if it’s more going on there.

 

All that and parking brake is also down?

 

Did you check the fuse too? Might save a trip to the dealer.

 

Yes. Parking brake engaged, 50% output. Brake disengaged, remains at 50% output.

Didn’t used to do that. Brake on, 50%. Brake off, 100%.

 

Gonna check fuses in a few minutes.

 

Gotcha, yeah you have something going on then. Could be a fuse, though I don’t know why one would just go bad like that.

My guess is that the main body ECU is no longer controlling that circuit like it’s supposed to.

If you don’t figure it out tonight, check tomorrow to see if your DRL works when you put it in auto in the sunlight (parking brake disengaged), since DRL is the same circuit as parking lamps with no fogs on.

 

Will do

 

so I’m checking the fuses and only found one (blue arrow) that is labeled DRL. Fuse was good. Replaced it anyways and nothing changed. Am I missing another fuse somewhere?

 

I don't believe so. @caribe makaira might have more ideas? I know there is a pin on the ECU that controls the DRL and stuff, but I am not sure which one, or if it is even worth trying to DIY if it's under warranty. If you have a meter or test light, I'd look at that green wire on the headlight plug, but if there isn't 12V there, let Toyota figure it out. If there is 12V there, then there may be something wrong with the headlights. Sorry I don't have a better solution for you.

 

It’s all good, I appreciate the ideas and suggestions.