2023 expedition max tail lights didn’t auto come on?

[justinj229]

Question here

So was driving home tonight and I kept getting flashed by cars behind me so I pulled into a Walmart and my tail lights weren’t on at all. My brake lights worked but taillights were not on. I looked and my switch was on the A auto for headlights which is what I keep it on. I did some tests when I got home and seems half my tail lights came in the top half but the bottom half is staying off on both sides. When I hit brake just the top half lights up not the silver part and below. Anyone seen this?

 

[99WhiteC5Coupe]

Question here

So was driving home tonight and I kept getting flashed by cars behind me so I pulled into a Walmart and my tail lights weren’t on at all. My brake lights worked but taillights were not on. I looked and my switch was on the A auto for headlights which is what I keep it on. I did some tests when I got home and seems half my tail lights came in the top half but the bottom half is staying off on both sides. When I hit brake just the top half lights up not the silver part and below. Anyone seen this?

Has the vehicle been repaired after damage to the rear end?

If not - warranty repair?

 

[SyndicateZ]

picture?

 

[justinj229]

Has the vehicle been repaired after damage to the rear end?

If not - warranty repair?

Carfax did actually say minor damage to rear

 

[justinj229]

picture?

 

[justinj229]

Both are same way if I hit brake top and bottom light up but when I drove the setting on dash was the one with the A for headlight switch - I pulled over and cycled through them and it went back to working. But the taillights I just see top lit up on both.

 

[justinj229]

Also added context my lane assist doesn’t work I see grey lines every time - could all this be related to the front camera being malfunctioning?

 

[justinj229]

 

[JamaicaJoe]

AUTO and Daylight Running Lights (Headlights) in many vehicles do not actually turn turn on the tail lights. It has been this way a long time. I don't know why the NHTSB does not reign in this potential hazard. I first learned of it driving a Jeep Grand Cherokee rental vehicle. I got pulled over by FHP trooper who kindly gave me advice on how it worked. No ticket.

 

[apex96]

AUTO and Daylight Running Lights (Headlights) in many vehicles do not actually turn turn on the tail lights. It has been this way a long time. I don't know why the NHTSB does not reign in this potential hazard. I first learned of it driving a Jeep Grand Cherokee rental vehicle. I got pulled over by FHP trooper who kindly gave me advice on how it worked. No ticket.

If a vehicle has auto dusk to dawn lights then the auto function will turn on the headlights and taillights when the photovoltaic sensor deems it dark enough. Now if your vehicle doesn't have this feature you wont have auto lights. You're confusing daytime running lights for automatic lights and they are NOT the same. Many cars have DRLs as they are now mandated to have them. Many people Also still think they need to manually control their headlights and turn the knob to the "O" or off position and then want to determine when to turn on their lights for themselves... problem is they fool themselves because DRLs are relatively bright in low light situations on most cars and those folks think their lights are on when they aren't.

Best advise I can give is turn the knob all the way to the right to the right and then back to the left one notch in the 2022+ expeditions as that is the auto light setting and will ensure the lights come on when it gets dark enough out. In bad weather you can go back one click further to the left right for manual light control (for when it's misting or dry snowing and the light conditions are bright enough not to trigger the lights and you haven't activated the wipers). I have a 2024 for work and just checked the light controls and they are different from the 2018-2021 expeditions as the flipped the Auto and manual light positions on the knob.

In the OP's case I believe he's got some electrical issues stemming from a previous collision. It's likely the shop did a botched repair and it will need to be properly diagnosed and repaired to bring back full functionality.

 

[justinj229]

If a vehicle has auto dusk to dawn lights then the auto function will turn on the headlights and taillights when the photovoltaic sensor deems it dark enough. Now if your vehicle doesn't have this feature you wont have auto lights. You're confusing daytime running lights for automatic lights and they are NOT the same. Many cars have DRLs as they are now mandated to have them. Many people Also still think they need to manually control their headlights and turn the knob to the "O" or off position and then want to determine when to turn on their lights for themselves... problem is they fool themselves because DRLs are relatively bright in low light situations on most cars and those folks think their lights are on when they aren't.

Best advise I can give is turn the knob all the way to the right in the expedition as that is the auto light setting and will ensure the lights come on when it gets dark enough out. In bad weather you can go back one click to the left for manual light control (for when it's misting or dry snowing and the light conditions are bright enough not to trigger the lights and you haven't activated the wipers).

In the OP's case I believe he's got some electrical issues stemming from a previous collision. It's likely the shop did a botched repair and it will need to be properly diagnosed and repaired to bring back full functionality.

Would a botched repair cause lane assist not to work? See the picture with grey lines?

 

[justinj229]

And on that note is this what everyone’s 2023 looks like? Seems more should light up when tail light is on is it just one bulb? The top? My bottom and sides do not illuminate at all

 

[apex96]

There's a possibility, yes. I don't have the wiring diagrams to dig into it further but it's likely the rear sensors tie in with the forward facing camera in one of the computer modules and if one of the paremeters it's looking for, from one of the sensors or camera, isn't met the system won't operate.

 

[apex96]

And on that note is this what everyone’s 2023 looks like? Seems more should light up when tail light is on is it just one bulb? The top? My bottom and sides do not illuminate at all View attachment 83466

Just checked my 2024 work STX trim and your normal rear lights look brighter than normal possibly. Here's photos from my 2024 for work with normal light and brake lights applied for comparison.

 

[justinj229]

I’m going to keep an eye on it the lane assist stuff is just weird and makes me wonder if it’s all same issue. Yes it had a rear “minor” accident per car fax but when my Acadia had that they really didn’t mess with the taillights much it was just back bumper and lift gate.

 

[apex96]

Just out of curiousity, how well marked are the roads around you? Are the markings missing or faded, or are they well marked and visible? If the camera doesn't identify the road markings it will not operate as well. Right now with the snow in the northeast, my 2018's LCA won't work as it cant identify the road markings well with all the salt and the damge done by the plow trucks.

 

[justinj229]

Just out of curiousity, how well marked are the roads around you? Are the markings missing or faded, or are they well marked and visible? If the camera doesn't identify the road markings it will not operate as well. Right now with the snow in the northeast, my 2018's LCA won't work as it cant identify the road markings well with all the salt and the damge done by the plow trucks.

I think the roads are fine it’s done this since I got it 4 weeks ago and I was on i75 going toward Atlanta and I noticed I was drifting and the lane assist didn’t do anything. Someone mentioned forscan and one of my #s being off as if someone maybe told it to stay off but not sure. All I see is gray lines like the system is deactivated

 

[apex96]

I think the roads are fine it’s done this since I got it 4 weeks ago and I was on i75 going toward Atlanta and I noticed I was drifting and the lane assist didn’t do anything. Someone mentioned forscan and one of my #s being off as if someone maybe told it to stay off but not sure. All I see is gray lines like the system is deactivated

I doubt somone modified the code to keep it off, it's literally a button on the wheel and once off it stays off and won't come back on until you press the button again. If you want to be sure, check the forscan section, I linked a website that will provide you the entire as-built code for you vehicle once you provide a VIN number.

Found the link: https://www.motorcraftservice.com/AsBuilt

You can go line by line in forscan and compare to the factory as-built code.

 

[justinj229]

I doubt somone modified the code to keep it off, it's literally a button on the wheel and once off it stays off and won't come back on until you press the button again. If you want to be sure, check the forscan section, I linked a website that will provide you the entire as-built code for you vehicle once you provide a VIN number.

Found the link: https://www.motorcraftservice.com/AsBuilt

You can go line by line in forscan and compare to the factory as-built code.

I think the user did this for me he put in my VIN and then found my code - not sure what all he did but said the difference in my code and his was off by a 0 or 1 can’t remember which.

I just drove the car around the block and tail lights stayed on. Now I’m wondering if it was just a glitch but there’s no dial that would keep headlights on without tail lights right? We usually keep it on auto and keep it but I played with dials tonight and didn’t have one that kept fronts and back off so not really sure. I’m pretty sure it was in auto when they honked unless somehow it was stuck in between the above and auto but even in that case not sure why the headlights would be on.

 

[apex96]

There's no way to keep actual headlights on without the tailights illuminating. Likely the button was in the off position and you didn't realize it. Shops normally turn them off when they bring them into the bays. Most times when I get mine back from the shop the lights have been turned off and I have to flip them back to the auto position.

The DRLs are extremely bright and they look like the headlights do... only way you'll realize the headlights have not been turned on is that all your interior buttons (HVAC controls, audio controls, door controls, etc...) should still be dark, they only become illuminated when you turn the headlights on.