Partial Tail light Failure

[FourdBanger18]

Partial tail light failure. Right rear tail light only flashes 2/3 leds. Prior to dealership visit today only the middle one worked. I tested two tail light assemblies but the same issue persists on either one. I’m thinking it’s the BCM, which they reset at the dealer. I asked them to flash ssm 47429, but the tech said he didn’t know what I was talking about. Walked in with a problem and walked out with the same one lol just kinda different. Should I buy a whole new BCM or go to another dealer?

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[Cobra Jet]

Try another dealership - print and bring the SSM to show them. Some of these guys are looking up your VIN in the Ford system - and when doing that it’s NOT going to show the SSM because the SSM is now an older document and it’s NOT VIN specific.

They have to manually plug in the vehicle year and model - then they have to go to the TSB/SSM/GSB section in the Ford system and look up that SSM # in order to find it.

If the Dealership cannot fix the issue via the SSM, then you will definitely need a BCM. Be sure you are purchasing the correct BCM, because the Coupe (fastback) and Convertible BCMs are different and are not compatible due to the difference between vehicle options.

Also to note, be sure you are also getting same model year BCM for your vehicle. On the exterior of the BCM case, there are white labels with production dates and codes as well as Ford Part #s. As long as the Production Date is within the same batch as your original AND some or all of the other codes/part numbers match your original then it should be the one you need.

 

[FourdBanger18]

Try another dealership - print and bring the SSM to show them. Some of these guys are looking up your VIN in the Ford system - and when doing that it’s NOT going to show the SSM because the SSM is now an older document and it’s NOT VIN specific.

They have to manually plug in the vehicle year and model - then they have to go to the TSB/SSM/GSB section in the Ford system and look up that SSM # in order to find it.

If the Dealership cannot fix the issue via the SSM, then you will definitely need a BCM. Be sure you are purchasing the correct BCM, because the Coupe (fastback) and Convertible BCMs are different and are not compatible due to the difference between vehicle options.

Also to note, be sure you are also getting same model year BCM for your vehicle. On the exterior of the BCM case, there are white labels with production dates and codes as well as Ford Part #s. As long as the Production Date is within the same batch as your original AND some or all of the other codes/part numbers match your original then it should be the one you need.

Thank you for you reply. Will be trying an eBay bcm tomorrow, hopefully it resolves the issue and if it doesn’t it wasn’t expensive

 

[FourdBanger18]

where is this located?

 

[FourdBanger18]

Update. Thank you cobra jet for your prior post of location. Both of my bcms are doing the same thing. Partial failure in right tail light. Car on, right signal, it hyperflashes and partial failure. I leave car on. Unplug bcm, reconnect. Bam’ it working again like normal for a while. I have a 2018 and the threads I’ve seen are relating to 17 and below. I’m more than sure it’s due to a bcm needing a reflash. Going back to dealer in the morning to see if they can flash it free of charge. Fudge

 

[FourdBanger18]

Is there a fuse like 1,6,7 I believe that controls the bcm that might be no good? Idk plz help

 

[FourdBanger18]

When I have the car on. Unplug the bcm while car is still on and reconnect. My partial tail slight failure is fixed. Therefore, is this relating to it thinking I have low battery while the car is just sitting? So the bcm reflash should work? Friggin dealership “reset” It. I asked for a sms reflash and they didn’t understand me. Guat da fack

 

[RIBS]

Wouldn’t this be under warranty? 3/36.

 

[FourdBanger18]

Wouldn’t this be under warranty? 3/36.

I fucked up by going with my euros on. So I replaced my battery and I’m still getting the same issue. Occasionally it fixes itself now. Voltage sitting at 14.3

 

[LarsenGrind]

I dont have quite the same problem, but after I had amber seqs installed in my EU spec'ed GT, sometimes the lights act up. The braking lights dont come on, when braking. So I have to turn the light switch to on and then back to auto. Thats fixes it. Atleast for that power-on cycle. And its only a problem during winter. Don't know if it draws more power than the car/BCM likes?

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