2010 Tacoma Headlight DRL question

Hello,

I just traded the Rubicon in for a 2010 Tacoma TRD Off-Road and noticed that the headlights don't actually turn off while the vehicle is on. I have searched many threads and don't seem to be able to find an answer to this. I see threads about the 2009-2011 DRL, but don't answer my question either.

My headlights, corner lights and tail lights will turn on when the truck is "on". Does not matter if the light switch on the stalk is "off", "parking", or "on", lights on no matter what. I have seen plenty of trucks just like mine with the lights turned off as they drive, so I was confused when Toyota told me that's how it's supposed to be. My wife's 2007 Camry has a DRL Off setting next to "Auto", but I don't have either. Just off, parking and on with the switch. I usually leave my lights on living in the PNW, but sometimes, you need to turn the headlights off.

I apologize if this has actually been covered 16 different times, feel free to post the link and I'll do some digging.

And yes, I am LOVING the Tacoma! The Jeep was fun, but when we had a baby and started doing much longer overland-style trips, we needed an upgrade. Already dumping paychecks into parts!

Thanks!
Austin

 

Welcome fellow PNWer! Where you located? I also came from a Rubi and went to a DCOR due to a baby.

Any chance your truck was imported from Canada? As the corner lights always being on is I believe a Canadian standard. That certainly is not the way the trucks came from the factory in the US. Or is there any aftermarket alarm/remote start?

Using the harness in this headlight upgrade will disable the DRL headlight function, but won't help you with the corner lights:
https://www.tacomaworld.com/threads/the-ultimate-headlight-upgrade-not-led-or-hid.398066/

 

Hello! I live in North Bend, just down from Snoqualmie Pass. I believe this truck came from California, not Canada, but I'll double check that. There is no aftermarket alarm or start system installed. I had the Toyota dealership look at it and they said "that's how all these trucks come"...I do not believe them. I see plenty of 2nd gens with their headlights off. Doesn't make sense! Hoping that if enough people chime in here and say that their headlights don't operate that way, Toyota will believe me. I'm about to head out onto their lot and start playing with the light switch on different trucks to prove my point

 

it makes you safer keep it and just enjoy the truck

 

The body ECU controls the headlight relay, which turns the headlights on and off. Try this and report back. With the engine running, headlight switch turned off, and headlights on, turn the engine off and remove the key. Do the headlights stay on until you open the door, and then go out when you open the door? If so, the ECU and headlight relay are doing doing their job properly. After you report back, we'll go further.

http://www.customtacos.com/tech.old...6toyewd/06toypdf/ewd/2006/tacoma/h/em01d7.pdf

 

Thanks @Muddinfun , I have checked and the lights (headlights, corner lights, tail lights) turn on and off when the key is on or off. They are not connected to the doors at all. As soon as the key hits "on" (not cranked yet), the lights all come on. When you turn the key to "acc" or "off", they lights all turn off (along with everything else in the truck). I appreciate the help!

Thanks @paranoid56 I certainly enjoy the truck! I need the lights to turn off at times, however, and have plans for a headlight upgrade with @kustom54lighting . Before I proceed, I want to ensure that everything works correctly.

 

That's really strange. So it would appear that the headlights are not being controlled by the body ECU, but instead wired directly to the key. Someone must have purposely done some creative wiring. Which dash indicator below do you have?

 

I have the USA headlight indicator.

 

OK, I'm at a loss. Look around under the dash and in the engine relay/fuse block for some creative wiring that doesn't look factory.

 

Thanks! I'll do my best with the diagram you posted.

 

I suppose there's a slim chance that there is some programming in the body ECU that tells the headlight relay to turn on the headlights whenever the key is on. Maybe the truck was a company truck and the company wanted the headlights "always on for safety".

 

Toyota said the programming looked "normal" when they scanned it. But I doubt they examined any wiring in the 5 minutes they had the truck.

 

I have a California 2010 Tacoma and the headlights are not on unless I rotate the switch. I do have DRL that are automatically on when the truck starts, no switch. The DRL lights up the parking lights (turn signals) in front.

 

Thanks @David K , that's what I thought. The DTRL are using the turn signal lights. Essentially, my "parking lights" aren't working either. I only have "headlights on" mode

 

When you turn the headlight switch from off to on, with the engine running, do the dash lights dim?

If you turn on the headlight switch on, without the key in the ignition on, do the headlights come on?

 

This might be something to look for. Look at the 2nd pic in post#10 and the resolution in post #14.

https://www.tacomaworld.com/threads/solved-how-does-drl-signal-from-body-ecu-work.322858/

 

I will have to check on the "dim" thing. But the headlights do not work without the key in the "on" position at all.

That link is very interesting! I'll dig into that more. Thanks!

 

I did check on the "dim" comment above. No, they interior dash lights do not change as you switch the headlights from "off" to "on". The "dim" setting for the interior lights is consistent as soon as the key hits "on". I am going to look at the wiring this weekend to see if my novice eyes can detect anything unusual. Thanks guys!

 

So, with that information, the headlight switch isn't doing anything at all. It appears that the Body ECU is not controlling the headlight relay, since the headlights don't stay on till you open the door. So, my best guess based on the info you provided, is that someone wired up a relay like in that link I provided. In order for that to work, they would have to have cut the wire between the headlight relay and the ECU and hooked it to 1 relay contact and the other relay contact to ground, then the relay coil would be hooked to ign. 12+ and ground. That way, the ignition energizes the added in relay, which completes the circuit to ground for the headlight relay. That's my best guess.

 

Sounds reasonable, thank you for your help! I'll look into the wiring this weekend, but am probably outside my scope. However, I have a lot more to go on with Toyota now and can hopefully get this sorted. I really appreciate the insight!