Mustang S550 - Taillight Issue On and Off!

[RalfTech]

Hello everyone,

I own a 2015 Mustang Ecoboost Premium and I have a big problem with it

One of the boards on my left tail light keeps going out and back on. I get it back on after I cycle/restart the car off and on. It affected my 4th brake light (Mpconcepts) badly so I disconnected it.

I’ve attached video of the issue w/ Forscan images at the end!

Help will be appreciated. I’ve read that I need to recalibrate my BCMB to latest calibration but its expensive at a dealer as I’m a student and I’ve worked hard to get this car.

P.s weirdly enough my Camera is being affected too... sometimes the cam works and sometimes it doesn’t...

Its a mess

B32A629B-5DFA-4AAB-9AAA-2F5183B8376C

• RalfTech
• Jun 3, 2019

4F1241FC-FC2B-467B-8E52-E7CDB758978A

• RalfTech
• Jun 3, 2019

9DA73554-3CE0-4C3B-8C08-3E8029BF3C63

• RalfTech
• Jun 3, 2019

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[JohnDoe]

Hello everyone,

I own a 2015 Mustang Ecoboost Premium and I have a big problem with it

One of the boards on my left tail light keeps going out and back on. I get it back on after I cycle/restart the car off and on. It affected my 4th brake light (Mpconcepts) badly so I disconnected it.

I’ve attached video of the issue w/ Forscan images at the end!

Help will be appreciated. I’ve read that I need to recalibrate my BCMB to latest calibration but its expensive at a dealer as I’m a student and I’ve worked hard to get this car.

P.s weirdly enough my Camera is being affected too... sometimes the cam works and sometimes it doesn’t...

Its a mess

B32A629B-5DFA-4AAB-9AAA-2F5183B8376C

• RalfTech
• Jun 3, 2019

4F1241FC-FC2B-467B-8E52-E7CDB758978A

• RalfTech
• Jun 3, 2019

9DA73554-3CE0-4C3B-8C08-3E8029BF3C63

• RalfTech
• Jun 3, 2019

I have the same EXACT issue today on my 2015! I'm going to try to disconnect my battery for 10 minutes and see if that resets the BCM

 

[JohnDoe]

Just tried disconnecting the battery and still no go. Guess I’ll be buying an entire tail light assembly. Maybe one of the custom chinese ones with yellow sequential turn signals built in

 

[ezracer]

I'm having "sequential" tail light issues. Dealer reflashed/updated BCM. That was good for a week. Another forum member "duckydave" has a similar issue and a dealer will be replacing his tail light tomorrow 7/26/19. I'll check with him afterwards to see if it worked. Also, many owners have wonky, on again off again back-up cameras. I do. I feel the 6th gen has a lot of electrical gremlins.

 

[CBDickens]

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

 

[RalfTech]

The BCMB update at the dealership helped me! I paid $150 and it was worth it. No more issues with the tail lights or any electrical mods I did to the car. It works!!! I still have the camera issue though... definitely the wiring that goes from the trunk to the car. I’ll try extending the wires and soldering them shouldn’t take longer than 30 minutes. Otherwise electrical is amazing.

 

[RalfTech]

I have the same EXACT issue today on my 2015! I'm going to try to disconnect my battery for 10 minutes and see if that resets the BCM

Won’t work sadly you need to update/recalibrate to latest release the BCMB at the dealership.

 

[JohnDoe]

Won’t work sadly you need to update/recalibrate to latest release the BCMB at the dealership.

What about changing the tail lights all together?

 

[CBDickens]

What about changing the tail lights all together?

No - my dealer changed mine and the problem persisted. I found that BCM update and brought it to them and they flashed and fixed my problem.

 

[JohnDoe]

I'm out of bumper to bumper coverage. How much did your BCM updates cost?

 

[CBDickens]

Mine was free outside of bumper to bumper.

 

[JohnDoe]

Stopped by the dealer today and they're backed up til next Tuesday, plus the labor will cost $140. I might as well buy a new battery and see if that fixes this.

 

[ezracer]

Stopped by the dealer today and they're backed up til next Tuesday, plus the labor will cost $140. I might as well buy a new battery and see if that fixes this.

YUP. I'm out of warranty and the dealer reprogrammed mine......cost ~$150. Fix only lasted 2 days. Just went to dealer again yesterday. They said the BCMB will not accept any more updates so they will replace it. It is on order. Will cost me $500. Ouch. Hope the hell it works. Sequential tail lights is the ONLY reason I bought a Mustang. (kidding)

ps: I'm not a Tech but I doubt a new battery will fix the problem.

 

[JohnDoe]

YUP. I'm out of warranty and the dealer reprogrammed mine......cost ~$150. Fix only lasted 2 days. Just went to dealer again yesterday. They said the BCMB will not accept any more updates so they will replace it. It is on order. Will cost me $500. Ouch. Hope the hell it works. Sequential tail lights is the ONLY reason I bought a Mustang. (kidding)

ps: I'm not a Tech but I doubt a new battery will fix the problem.

Yup, got new battery last night and it didn’t fix anything but at least my voltage is over 14 now

 

[ezracer]

Yup, got new battery last night and it didn’t fix anything but at least my voltage is over 14 now

Apparently, the origin, or the cause of tail light issues is not caused by any one particular failure. One member ( duckeydave) on the 6th gen forum replaced his tail light...problem fixed.

Several members re-programmed the BCMB. Some lights were fixed others were not.

Currently, my BCMB will not accept any updates. Dealer says to replace the BCMB. Car currently in shop. I don't know what I'll do if the new BCMB
does not work. Dealer will need to contact a FORD Factory Rep. probably. Will keep everyone posted.

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