Automatic Headlights On During Day

[nfancera]

I just started seeing this on my 18 ST and can't find anything on the forum. I keep my headlights set to auto with fog lights at all times, but recently they have been coming on during the day.

Does anyone have experience with this or ideas on what to check?

 

[Dialcaliper]

I just started seeing this on my 18 ST and can't find anything on the forum. I keep my headlights set to auto with fog lights at all times, but recently they have been coming on during the day.

Does anyone have experience with this or ideas on what to check?

Have you checked the BCM for codes?(Forscan or other diagnostic can check for this). Might be the little sensor on the dash either failed or lost connection - the auto headlights turn on and off based on input from that sensor, and if there’s no signal, it probably fails to “it’s dark out”

Sidenote, apparently that sensor also feeds into the climate control - apparently cooling compensation for bright sunlight), so you might also be experiencing poor cooling performance with the climate control on auto.

 

[Intuit]

Is your Sync3 display switching to night-mode? (note: check options for automatic/light/dark and set to auto)

Can you turn the headlamps off?

Have you tried temporarily pulling the battery negative cable?

.

 

[Cneu]

I'll toss this out there. The sensor is the lil black nub behind your sync 3 screen underneath the center front of the windshield. Do you happen to have anything on top of that sensor?

also, be aware that in many states(I think most?) it's illegal to use your fog lights if your brights shouldn't be on. The wording is often something like "Fog lights are illegal in any situation where dimming the headlights is required." So in city limits, when there's oncoming traffic, etc. It's not enforced but the laws exists for a reason. Auxiliary lights are considered brights in most states.

 

[nfancera]

Thank you for the input guys. To answer some questions:

I ran for codes and I'm coming up with none.

I can turn the lights on and off, everything works perfectly on the non-auto mode.

I did try disconnecting and reconnecting the battery in full and the problem continued.

I didn't think about the sensor itself. It isn't covered, but I did recently have my interior detailed. Potentially they left a wax or build up on it that is messing with the sensor. I will clean that today and see if it resolved the issue.

Huge help guys, I appreciate it.