Tail lights not working

[sms2022]

My electrical woes continue…Brake lights work, turn signals work, but the taillights are not on with the headlights. Anyone had this happen?

had someone completely flip out and road rage on me tonight because of it, unnecessary but it did bring the issue to my attention lol

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[MiamiGT350]

I don't believe there is a fuse for tail lights, and they are instead controlled by the BCM (body control module).

I would disconnect the battery for a few minutes and see if they come back on.

Reply back if it doesn't resolve it.

 

[sms2022]

I don't believe there is a fuse for tail lights, and they are instead controlled by the BCM (body control module).

I would disconnect the battery for a few minutes and see if they come back on.

Reply back if it doesn't resolve it.

Tried this last night. It did not fix it. Called my dealer earlier and they had no clue. Given all the dtc codes coming from my bcm they said to bring the car in next week and they’ll replace it.

 

[MiamiGT350]

Sounds like the BCM might be toast, especially if issues have been on-going.

 

[sms2022]

Going to try an as built bcm reset with Forscan.

anybody have any other last ditch ideas? Would really prefer to not take it into the dealer if possible

 

[GilmourD]

If I'm reading these diagrams from other posts correctly you should have voltage between pins 2 and 6 with the headlights on. Pin 3 is the bright for the outside, pin 4 for the middle, and pin 5 for the inner.

This?

I didn't want to mess with pulling stuff apart again, so I just made this diagram. This is the way both plugs should look for a 2018-19 tail light to work properly.

So to make everything very clear: If using the 13-14 harness I linked above, the 5x2 plug is already set up correctly, with the addition of a 7th, blue wire that is unnecessary (I am not sure if it could be left untouched as I ended up removing mine before getting this harness to work). The 4x2 plug requires all wires to be moved 180 degrees (this means that the black wire was actually in the red spot originally, the grn/wht was in the red/yel spot originally, etc.). The only exception to the 180 degree rotation is that the solid red and the red/yellow wires must be swapped. But obviously no need to worry about that as anyone now can follow the diagram above which is correct. (If you do get it wrong, your turn signal sequencing will be opposite, i.e. it will sequence from the outside in. In which case just flip the solid red and red/yel wires.)

 

[sms2022]

Total bcm reprogram and pcm relearn fixed it

 

[TonyNJ]

Did you have the BCM recall performed? Or was your car not part of that? I had it done on my 2020PP2 and 350/500s.

 

[sms2022]

Did you have the BCM recall performed? Or was your car not part of that? I had it done on my 2020PP2 and 350/500s.

Had it done last time it was at ford for the AC going out. Doesn’t affect anything here though, it just recalibrates the brake fluid sensor.

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