I need help. The brake lights are messed up

[Mike Pfeifer]

Based on what you have already tried, it sounds like one of two things: the control module that controls the light or the wiring between that module and the light. As said above, it could be a software fix and I would try that first. If that doesn’t do it, you can check all the wires between that taillight connector and the module. If they are OK, then it will probably need the module replaced and programmed. If the wires are not OK, then fix them and re-test. You are just eliminating parts of the circuit until there is only one thing left.

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[dirtwarrior]

Thanks for all the replies. It will help me and help the next person with this issue.

 

[dirtwarrior]

The wires and wiring harness is intact. To recap what I did so far.
Unhooked + and - from battery with a jumper between the cables
Tried a new light
Inspected the wires and harness
Charged battery
No change in the last tribar lighting on brake and turn.
Should I spend money to get BCM-B reprogrammed?
If I buy a good used one will it need programming?
Does the trunk mounted BCM-B just control the rear lights?

 

[luca1290]

Should I spend money to get BCM-B reprogrammed?
If I buy a good used one will it need programming?
Does the trunk mounted BCM-B just control the rear lights?

The TSB asks for reprogramming as first diagnostic step, I will do that.
It will need programming. Usually Ford diagnostic software do coding when you install a replacement module to program it to your car's features.

No, it controls also other things (i.e. MyColor)

 

[dirtwarrior]

Thanks for the reply

 

[mtmtko]

This may be unrelated but I had a case that both taillights weren’t showing a brake signal - the third brake light worked thou. I even tried it with a new taillight - same thing. I ended up doing a system diagnostic procedure with a obd scanner that did a quick check of lighting , horn and some other things. That solved the problem in my case.

 

[dirtwarrior]

This may be unrelated but I had a case that both taillights weren’t showing a brake signal - the third brake light worked thou. I even tried it with a new taillight - same thing. I ended up doing a system diagnostic procedure with a obd scanner that did a quick check of lighting , horn and some other things. That solved the problem in my case.

Did the scan show anything? All you had to do is the scan? I will try this.

 

[mtmtko]

It was enough to run the selftest - during the test the taillights started working again.

 

[dirtwarrior]

It was enough to run the selftest - during the test the taillights started working again.

I am interested. Which scanners do this?

 

[mtmtko]

That’s the one I used: https://amzn.eu/d/dt9mq12

but this should be possible with forscan as well.

 

[luca1290]

I am interested. Which scanners do this?

Use Forscan with this: OBDLink® EX - OBD2 Adapter For ELM327 & FORScan it's the best adapter for Forscan (check for new adapter firmware before using it).
I don't remember if BCMB has a self-test feature tough.
The main BCM surely does, probably it's integrated in this.

 

[mtmtko]

This is the self-test I meant in forscan. It’s the highlighted one.
if you have forscan it’s worth a shot.
As Luca mentioned for forscan the obdlink ex is the best adapter.

 

[dirtwarrior]

I do not have a smart phone. My computer is a desk top. Is there one with an intergrated screen?

 

[Superspirit]

Nope. forscan works with a windows laptop.

 

[illadvised]

For forscan, get an extension cable and power strip and then set up the PC in the driver seat with monitor in the passenger seat. Or you'll have to borrow a laptop from someone

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