For an upcoming Project i wanted to understand how a Radio in a Renault Megane Scenic 3 "talks" to the Display to show informations. (Megane 3 : 2008 - 2016) 

I started by looking for wiring diagrams to see how everything would connect in a real car. 

Of course i went to my local Renault dealer to look up the diagrams and i have not downloaded them from the internet. This is why i dont know that wiring diagrams from Renault are called "Visu" and have a numbering system starting with "NTxxxx" followed by 4 numbers (x) wich represent the type of car.

Let me sum up the things i have learned from the wiring diagrams first and the pick up on the important points:

- Megane (Fluence) and Scenic are basically the same cars underneath. 

In the Megane/Flence you have a Cluster and a seperate "Info Display". The "info display" can also be a Monitor if you have the TomTom Navigation option.

In the Scenic the Cluster is the "info display" at the same time. in addition to the Cluster you could order the TomTom Navigation monitor.

The components of the Multimedia system use Can-Bus to communicate. It is a 500kbit/s Can Bus system.

- Megane and Scenic share the same types of Radios. 

That was a useful information... BECAUSE : i looked up the radios that could be fitted into Megane Scenic. And i found out that the same Radios (with slightly different faceplates) are also in A LOT of other Renaults from this time ... Like Twingo, Master, Wind, Clio and of course Megane Fluence and Scenic and all models i forgot to mention.

In short: If your display looks like this (or similar)it will most likely work. Note the bars above and below the row of text! 

As i said on Scenic the Display is integrated into the Cluster and looks like this:

The third Option to use the Display data is to show it on the TomTom Navigation System wich looks like this:

I was amazed how much this protocol was used by Renault and decided that it might be really useful for a lot of people to know how to use this in projects. 

As soon as you take out the original Renault Radio and replace it with something different the display is is unused. Or wouldnt it be really awesome to display some kind of information like a voltage or temperature? Or even a own menu structure to set things or make stuff happen? So much potential...

SO i started to order some Hardware to reverse engineer all of this. And the fun begun.

The tools i use i will discuss in the next episode of this blog. We will focus here on the Car Hardware.

Because i i didnt know all the details i described above i started to order random Renault Radios from around the time renault made the megane 3. 

And i also ordered a scenic 3 cluster from 2013... because it was the cheapest one i could find for around 20 Euros. Wich looks like this:

The price range for scenic 3 clusters is amazing... from basically nothing to "are you kidding me" ... Some sellers think that a TFT Display from a 14 year old car that sold A LOT of units is still worth 200+ Euros... But... lets just continue with the story.

The first Radio i got for my experiments was a from Renault Laguna.

It looked quite similar to the Radios from Megane and it was again the cheapest one of the radios that looked similar to the ones i need.

(How i got the scenic cluster running will be another Blog.)

I connected everything together and ... Nothing. 

Nothing isnt quite right... The hardware seemed to do nothing but on my Can Bus monitoring software i saw that there was some activity. So it must be connected right. The Radio started to send something and the cluster responded. But nothing more happened when you pressed buttons on the radio or the radio remote.

Ok. My fault. I should not order stuff that "looks similar" to what i need. Lesson learned. Order the next radio. This time i ordered one from a Megane 3 from 2009. Wich is exactly what i need.... I foolishly assumed... Wich looks like this:

I connected my Scenic Cluster to my (Megane)Scenic Radio and ... the same thing. Can-Bus does stuff... Radio and display not. 

At this point i knew i had to dig a little bit deeper into all of this. No problem... I love a nice challenge.

I stopped hardware Buying for a moment and focused a little bit more on research.

Because i have a background in car mechanics (especially Renault and Dacia) i was already familiar with Software like DDT 2000, Clip, Pyren or DDT4ALL . 

So i started to look around in the coding of my Scenic cluster if i can find something that has to do with the Radio. And yes... i Found this in the settings for my 2012 Cluster:

There are different settings for the type of Radio... Thats a nice discovery.... 

I instantly tryed all possible settings with my Megane Radio and... still Nothing... I was getting a little bit confused... I found the right setting, bought the right Hardware and NOTHING! Why?

I loaded another Diagnostic file in the software for an older version of the cluster to see if there are other options to set... And yes... Its called a little bit different there... Thats interesting...

In the first Screenshot of the settings you see things like "non utilise" and "ex radio ..." wich says something like "no longer used" and "previously known as ...".

For the next 2 days i just looked at pictures of Scenics on car selling websites... And yes... At around 2012 Renault has updated the Audio system to use different Radios... And i have discovered that there are exactly 3 general versions of the Scenic cluster... I could point out pretty precisely when renault phased in and out the versions of the Scenic cluster:

The cluster i have is from mid 2012 so it is a "Version 3"...

The next goal should be clear now... Of course i did the reasonable thing ... buy more random stuff until i have all 3 versions of the cluster... Because i did my homework i could find out wich version of the cluster i would get based on the production date sticker.

I ended up with "just" 3 Clusters... And now i have all general versions of the cluster to experiment with.

And i could even get them for just 15 - 25 Euros. 

The next Step was to connect my Megane Radio to an older version of the cluster. And... of course it didnt work. But no panic. I changed around the Settings we saw above, and it finally started working.

PARTY!

The setting it started to work is "radio R1" ... So i will call the Hardware and protocol used "radio R1".

And that is basically everything my first phase of hardware research has evolved to... A working setup AND the information that Renault removed the "radio R1" support around 02/2012.

My Megane Radio also came with the basic Display wich at this point was just a "nice to have" bonus item, but will become very important in the next part of this Blog. 

Next time we will discuss the Tools i use to spy on and emulate the CAN-BUS, and my first steps to make things do what i want ;) ...

Have a productive day and until next time.