Peugeot 407 SW 2007 2.0 HDI: Rear Left Turn Signal Not Working, BSI Error B4BD & Pin Info

Or maybe something is wrong with the lamp itself? try to make mux cables to swap the right and left directions and check the effect.

Aleksander_01 wrote:

BSI error B4BD (short to rear left turn signal) appears.

If it shows a short circuit, it won't help you:

Aleksander_01 wrote:

If I continue to blow it in ... I will solder the light bulb directly to the cables

think for yourself
maybe something wrong with the fiber, it shines but it has a short circuit for the computer?

As if the short circuit was in BSI, the bulb would not go out and there would be no short circuit fault to the ground because it is physically impossible.
It looks like the bulb just burned out the mass because it took too much electricity and you know how now everyone cuts costs, he repaired the mass but the bulb was probably the same.
My suggestion to swap left with right seems quite sensible in your case.
According to this algebra: ch. Mass + ch. light bulb = true
good weight + ch. light bulb = error

Aleksander_01 wrote:

Gentlemen, I have something lucky these peugots lately, but so far it has always helped download the clamp, even a few days ago one customer over the phone suggested what to do, in a moment he called and thanked.

Not only peugeots experience such a defect but it is strange that here the disease affects only one specific circuit. Since it helps to remove the clamp, it is obviously a computer reset, the mystery is why the reset does not occur after the ignition is turned off. You just have to remember that this direction is used in emergency which operate without a key and that would clarify the matter.

I have already suggested to you to change the left direction from the right direction twice and I will not be there anymore.
In the end you have to decide on something and cut the wire anyway to exclude accidental short to ground (it may well be a temporary short to the alloy wire in the ankle) e.g. as a result of rubbing the wire insulation.