Audi

Audi A4 B8 – The Dead LED’s in the Taillights

Posted on by bogdan
20
Jan

Although you don’t see it when driving … I consider this problem one of the most annoying things that can go wrong with your Audi.

Let’s take a look at what might be the cause and how we can fix it !

Bogdan

Hello everyone I am Bogdan, and in this post we will be taking a look at the so called “Dead LED’s” from the Tailights of the Audi A4 B8.

This was one of the first problems that I was faced with in my ownership of the Audi A4 B8. I have bought the car with multiple LED’s dead/not working properly on the taillights.

I was thinking that it will be an easy fix, I was working all day long in the Automotive Lighting business … How hard can it be ?

What is the cause for this problem?

After opening the LED taillights on my Audi A4 B8, I have proceeded in inspecting the board and could not find any major electrical fault, or corrosion due to water.

Strangely when I was applying pressure to the so called “dead LED’s” they would start to work properly.

Taking in account that all the “dead LED’s” that I have seen on the A4 B8 platform are on the tailgate/booth lid modules, I can say that the main contributing factor to this problem will be a mechanical-vibration related one, caused mainly by the way in which we close the booth.

How can you fix this problem?

The main options are:

  • Replace the affected LED modules completely
    • low risk
    • faster
    • more expensive
  • Open LED taillights and replace affected SMD LED
    • higher risk
    • takes longer
    • less expensive

Opening and repairing the LED modules:

A very good tutorial that I found on this topic is from the guys at Audizine and it is linked here.

The risky part is being able to crack open the taillight and not damage it completely. For doing this I would suggest replacing the screwdriver with a pizza slicer.

With the pizza slicer you are able to distribute the pressure better and reduce the risk of cracking the plastic uncontrollably.

If you have decided in doing this repair, my advice will be to change all the LED from the module so that you will not have another SMD LED fail immediately after finishing the work.

The technical details for the LED’s from the Audi A4 B8 taillights are :

Osram Opto LS E6SF-V2BA-1-1, 
Power TOPLED Series Red LED, 
633 nm, PLCC 4, 
Round Lens SMD Package

 
LED Colours Red
Package Type PLCC 4
Mounting Type Surface Mount
Number of LEDs 1
Forward Voltage 2.15 V
Luminous Intensity 1.6 cd
Number of Pins 4
Viewing Angle 120 °
Luminous Flux 4.65 lm
Lens Shape Round
Dominant Wavelength 633 nm
Dimensions 3.4 x 3 x 2.1mm
Series Power TOPLED
Lens Colour Clear
LED Material AlGaInP

I hope that this post helps. If you have questions or suggestions get in tough. We are UK based and specialize in Automotive Lighting.

bogdan