Tail Light Out, Then Back On

Had the car out last Friday and Saturday and both days the right rear tail light bar for blinker was out, cluster display going fast when right blinker was on. Saturday I pulled the sub out of the trunk and reset the harness plug to the light fixture and problem was still there. I figured since I have warranty and the fixture is so expensive I'd take it to the dealer.

Got there and now the light is working. I told the adviser to keep it over night and try to get the problem to resurface tomorrow. My question is, has anyone had the light go out and come back on and how did it turn out for you long term?

Turned car off and back on and problem never reappeared for me

I turned mine off and on several times which is why I took it to the dealer which I absolutely hate doing. I have to take my blown/stroked '05 there for both airbag recalls too. I'll be sitting and waiting for that job.

Join just to post here. I have a 16 GT and I been having this problem for months. The right section on the right taillight goes out. If I power cycle the car a few times it goes away. Dealer checked it out and said nothing is wrong. Anybody found I cause or fix?

Mine was fine when I took it to the dealer and it's been fine ever since. Only acted up for 2 days.

Anthony 05 GT said:

Mine was fine when I took it to the dealer and it's been fine ever since. Only acted up for 2 days.

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Been to the dealer 3 times. Every time they can’t find anything wrong.
Mine has been doing it since month 2. Cycle the car, everything is working again. It is so weird.

Was leaving my parents house last night and my step-dad texted me saying that my right rear tail light was out. Pulled over and did some tests. Very strange in that the turn signal works fine, AND it lights up fine when I hit the brake, but with just the headlights on, it's dead.

That said, I did not try a restart. Will take another look today to see what could be happening. I know it can't be the LED's burnt out since the brake and signal work so I'm not sure what would've caused the issue. Hopefully it resolves itself tho as I'm out of warranty.

I should add that my car was rear ended several months after purchase in 2015 and I recall the left tail light being replaced because the black surround was cracked. I believe it was around $1000 just for that unit. Not sure if the work involved in tearing everything apart and repainting back then could have anything to do with this...

Mine has been good ever since the 1st episode

This might help, I don’t understand why dealerships don’t know this.

SSM 45895 - 2015-2016 Mustang Built On Or Before 4/22/2016 - Rear Tail Lamp, Turn Lamp Or Stop Lamp Partial Outage - DTCs B1271, B1272, B1273, B1274, B1275 or B1276.
Some 2015 and 2016 Mustang vehicles built on or before 4/22/2016 may exhibit a partial outage of the rear tail, turn signal or stop lamps following a vehicle start with a low battery. This may be accompanied by any combination of DTCs B1271, B1272, B1273, B1274, B1275 and B1276. The condition typically clears on vehicle restart. Reprogram the BCMB module to the latest calibration using IDS release 101.01 or higher. Calibration files may also be obtained at www.motorcraftservice.com. Use applicable labor operations from Section 10 of the SLTS manual and use causal part 13C788

Interesting! Mine doesn't get driven that much which explains this is possible in my case. I've got 6400 miles almost 3 years old.

JOKER GT said:

This might help, I don’t understand why dealerships don’t know this.

SSM 45895 - 2015-2016 Mustang Built On Or Before 4/22/2016 - Rear Tail Lamp, Turn Lamp Or Stop Lamp Partial Outage - DTCs B1271, B1272, B1273, B1274, B1275 or B1276.
Some 2015 and 2016 Mustang vehicles built on or before 4/22/2016 may exhibit a partial outage of the rear tail, turn signal or stop lamps following a vehicle start with a low battery. This may be accompanied by any combination of DTCs B1271, B1272, B1273, B1274, B1275 and B1276. The condition typically clears on vehicle restart. Reprogram the BCMB module to the latest calibration using IDS release 101.01 or higher. Calibration files may also be obtained at www.motorcraftservice.com. Use applicable labor operations from Section 10 of the SLTS manual and use causal part 13C788

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Oh wow! Yes! That's exactly what I've been experiencing. To follow this up, I'm definitely still having an issue. It's really freaking annoying. I've constantly been pulling over into parking lots to get out and check. Sure enough, half the time, it's out.

To be clear, my tail light appears to work perfectly EVERY time as a brake light or a turn signal. Where it intermittently fails is as just a parking light (when headlights are on). I'll get out of the car to check and it may be on. 10 minutes later if I check again, it may be off. I'll switch the headlight knob from "Auto" to "On" (or restart) and it will come back on. I'll get home and check and it might be off. FML.

So Joker GT, what exactly is that you posted? Is that a recall a TSB? My car is out of warranty but given that this appears to be a known issue and is safety related, should I be charged an exorbitant fee by the dealer for the fix? Is there any known way I can do the update myself or have it done at another shop?

MSMStannyl said:

Oh wow! Yes! That's exactly what I've been experiencing. To follow this up, I'm definitely still having an issue. It's really freaking annoying. I've constantly been pulling over into parking lots to get out and check. Sure enough, half the time, it's out.

To be clear, my tail light appears to work perfectly EVERY time as a brake light or a turn signal. Where it intermittently fails is as just a parking light (when headlights are on). I'll get out of the car to check and it may be on. 10 minutes later if I check again, it may be off. I'll switch the headlight knob from "Auto" to "On" (or restart) and it will come back on. I'll get home and check and it might be off. FML.

So Joker GT, what exactly is that you posted? Is that a recall a TSB? My car is out of warranty but given that this appears to be a known issue and is safety related, should I be charged an exorbitant fee by the dealer for the fix? Is there any known way I can do the update myself or have it done at another shop?

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That is interesting, my issue was the opposite. It worked perfectly fine as a running light but then the middle bar would not illuminate under braking or during a turn signal. After a few months of this intermittently happening, it just went away, and it hasn't happened even once now for a good 2-3 months. *knock on wood*

I still have no idea what caused (or even fixed) the issue.

MSMStannyl said:

Oh wow! Yes! That's exactly what I've been experiencing. To follow this up, I'm definitely still having an issue. It's really freaking annoying. I've constantly been pulling over into parking lots to get out and check. Sure enough, half the time, it's out.

To be clear, my tail light appears to work perfectly EVERY time as a brake light or a turn signal. Where it intermittently fails is as just a parking light (when headlights are on). I'll get out of the car to check and it may be on. 10 minutes later if I check again, it may be off. I'll switch the headlight knob from "Auto" to "On" (or restart) and it will come back on. I'll get home and check and it might be off. FML.

So Joker GT, what exactly is that you posted? Is that a recall a TSB? My car is out of warranty but given that this appears to be a known issue and is safety related, should I be charged an exorbitant fee by the dealer for the fix? Is there any known way I can do the update myself or have it done at another shop?

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I don’t know if this can be done out of warranty, if you find out it can be please let us know. I have been told this can only be done through FORD as a typical shop is locked out from accessing this update.

DJRoy28 said:

That is interesting, my issue was the opposite. It worked perfectly fine as a running light but then the middle bar would not illuminate under braking or during a turn signal. After a few months of this intermittently happening, it just went away, and it hasn't happened even once now for a good 2-3 months. *knock on wood*

I still have no idea what caused (or even fixed) the issue.

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Yes, this it the typical scenario

DJRoy28 said:

That is interesting, my issue was the opposite. It worked perfectly fine as a running light but then the middle bar would not illuminate under braking or during a turn signal. After a few months of this intermittently happening, it just went away, and it hasn't happened even once now for a good 2-3 months. *knock on wood*

I still have no idea what caused (or even fixed) the issue.

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Did you get a new battery by any chance? Or did you take your car in for service where they may have updated the software?

As for what is actually happening, it sounds like that notice from Ford covers all of the scenario's so I guess it's just a random thing as to whether it's a brake light, tail light or turn signal outage.

I don't know the details of how it's built but I assume it's simply 3 LED chip boards, one for each bar. They simply light up as needed for the condition. That's what makes it especially strange to have it still work as a brake light and turn signal, implying that all boards are working fine, but then it not work as a tail light. Freaking weird...

I will contact dealer and/or Ford today and see what comes of it. As it stands, it's driving me crazy. I'm constantly paranoid the taillight is out so I just don't drive it at night. We take my GF's car everywhere.