Dynamic indicators LED issue

[asedas]

Hi all,

I'm struggling with strange random issue. I've put dynamic led turn signal indicators on my van, but they started blinking fast (hyperflash) from the time to time. It's totally random, it starts, then after while works normally, then hyperflash again, goes back, etc. No errors in logs (long time ago I had bulb warning but disappeared "immediately"). I thought it's light itself but took it off and checked offline and looks like working... what that could be? relay?
Second thing is that I've noticed that there are some turn signals relays designed for led... should I have such?

Thanks for advice

 

[Robert]

As I have mentioned before(somewhere else) some sequential LED strips are voltage sensitive.
For example they work perfectly with 12V DC and then they misbehave with increased voltage of 14.5V DC(when engine is running).
Luckily these strips are very rare and majority of recent/modern strips cope very well with increased voltage.

Then there is another trap .
Indicator's pulses can be PWMed(Pulse Width Modulated) and this is controlled by the BCM coding.
Almost all aftermarket LED strips don't like PWM and they won't work properly, especially when engine is running.

This is how indicator pulses look like when PWM is ON and engine is running.

View attachment 68152

And this is how indicator pulses look like when PWM is OFF and engine is running.

View attachment 68153

To deactivate indicator PWM the following VCDS coding modification needs to be applied.
09 BCM, (Byte 19, bit 3) = 0 (unticked)

View attachment 68158

 

[asedas]

@Robert you are brilliant... savior! looks like it, I will try and test. Thank you!

 

[nags]

The controller thinks theres a blown bulb
Put a resistor across the indicator, (value 6R 50W) by connecting it between the indictor wire and ground.
Search for "Canbus resistor" on eBay or Amazon to find.

 

[FWhite]

Hi Robert, good catch! I wonder why they would do that though. I understand for the rear position lights shared with the stop and the front position shared with the DRL (both on T6.1) , but the indicator?

P.S. nice Fluke Scopemeter. I have a '97 model 123 that I still use everyday. Built like a tank!

 

[DanW81]

You are a very knowledgeable chap robert. I have a t6.1 but have read some of your retrofits and the knowledge you speak of as made my retrofits a lot more easier to understand. Especially leuchte channels and PWM