Probably, they were flickering too so had to get capacitors to make them stop.

But didn't have to coded them off for errors though.


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When did they flicker? At first start up or all the time when they were lit?

From the moment I plugged mine in and turned on the car. Would stop if brakes were applied but otherwise it would constantly flicker.

Searched and it's due to the pwm on facelift cars and lightwerkz sold premade capacitors for the e53.


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It most likely is the after-market wiring...

The BFD feature is provided via PWM to the top lamp. The lamp is a 12v 21W single filament lamp and as a tail lamp it has a PWM pulse duty-cycle of about 20-30% - which makes the 21W lamp glow dimly like 5W or 10W tail lamp. When the BDF lighting is called for, the PWM duty-cycle changes up to about 90-100%, so the lamp glows like a 21W (brighter!).

LEDs cannot easily vary their brightness, although oddly enough the best way to dim LEDs is with PWM, but not quite the same system that BMW use on the OEM tails. So the after-market LED tails glow the same regardless of the PWM duty-cycle. The manufacture then has to wire them such that they are either on or off - possibly in groups to provide both tail and brake lighting behind the same lens. And the capacitors that are used to removed the "flicker" (which act as averaging devices) also screw up any chance of using BMW's PWM on after-market tails.

I'm guessing this is why there are so many after-market LED tail options for pre-facelift cars (which don't use PWM) and hardly any for facelift cars - it's just too hard for the after-market manufacturer to deal with the PWM. :dunno:

Well, that solves that... Great post Wayne.

Turns not in. Brakes and Backup installed.
No errors

Going to need caps....flickering galore
And or going back to stock.

Going to have to wait for night and give it a night test to see output

Is voltage monitoring coded off? That's what will cure the flicker. Do they work properly other than the flickering? Resistors are typically needed for signal lights, not sure about the brake or backup yet as I have not done those on my truck... yet. ;)

Mine's a pre. Dunno if there is a difference on how the voltage is sent vs post, vs coding ?
I'm going to have to spend some time reading older threads.
Does pre/post both have the top red lamp with a 21/5 bulb


Going to need to do a more real test with a human (wifey).
I put the bulbs in, set the iPhone on video and pulled the car front and backed in.

No flickering on backups though

Is yours constantly flicking or only on start up?

As far as I know, pre-lci don't have pwm voltage so should only flicker on start up due to the cold check which can be coded off.

Is yours also hyper flashing?


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Turns have not come in yet.

Not really testing much, as I got other issues going on on the X.
However, a quick light test - the red LED bulbs in the tail for sure are brighter !

I did not noticed any flickering. Maybe it's just due to how the iPhone picks up the LED on video - dunno. It was a short video test I did though. When backing up, it showed no flickering on backups, and the reds where flicking until I hit the brakes. Not really conclusive

More light testing once the turns come in.