silkworm

Hi,

I retrofitted the RSE system on my Audi A8. I used OEM devices, as I managed to get the entire assembly from an old car. It's the first version of the RSE - the one with Alpine DVD-changer and Alpine displays in the headrest.
I heard that there is a newer version with a set top box which allows the DVD changer to be controlled directly from MMI console (mine is controlled from a remote control). It would be nice to get that, but the donor car had this version so that's what I have installed at the moment.

Although the devices are OEM (they even have '4E0 ...' part number on them), originally Alpine did not make them for Audi, so they don't have the MOST connector. Thus, they can't be powered on like the devices on the MOST ring (those devices are actually powered by a permanent +12V - KL30, and woken up by a MOST ring signal or by the 'ring break diagnosis' wire).

So Audi implemented a clever way to power up the RSE system: it is powered on permanently, so you can remove the DVD cartridge from the changer anytime (just like you can remove the DVD from the NAV unit), but the system is woken up and kept awake by a second +12V wire from a relay.

The relay is sending the +12V signal when it receives another +12V input signal, so I got the input signal from KL15 (fused), but it turned out not to be such a good idea.

Normally you can listen to music (or watch TV or a video) even when no key is in the ignition - that's why all MOST ring devices are powered from permanent +12V. But since the video signal from TV tuner to the FBAS connector of the head unit passes through the RSE system, the RSE system should also be powered on when the TV tuner powers on (along with the entire MOST ring), otherwise the TV tuner can't be controlled.

So: getting the input signal from KL15 is a bad idea, I have to get that signal from something that turns on when the MOST ring turns on, and turns off when the MOST ring turns off.

I measured the pins from TV-tuner, RADIO unit and NAV unit. I could get voltage on some pins only when those units were awake, but the voltage is 5V (for RADIO) and 3V (for NAV), and I need 12V for the relay to power on the RSE system.

And now my question is: where can I get a +12V voltage that is in sync with the MOST ring devices (that means steady +12V when MOST ring is awake and 0V when MOST ring devices are in standby)?
The voltage will be used only as an input signal for the relay, it does not have to sustain heavy load.

I looked into Audi documentation for the electrical system and it seems that I need to connect the wire for the relay input signal to pin 6 of the trail controller (that's how it was also connected on the donor car), but my car doesn't have the trail controller and I don't want to retrofit that too

silkworm

Hello, It's me, again

As a non-native english speaker, I was wondering if my previous post makes sense, and if any of you understood what I was asking

So I did some further research and found out that pin 8 of the BOSE Amp should send +12V (only when the Amp is awake) to the subwoofer which is located in the parcel shelf. The bad part is that my voltmeter shows only 8V on that pin. I removed the pin from the connector, just temporary, to let the subwoofer unpowered to see if the voltage improves, and it does, but 10.5 - 11V is still not enough for that sensitive relay, so I really need at least +12V as an input signal or I will have no power to my DVD changer.

I was wondering if the yellow wire at pin 3 of the CAN Gateway (J533), labeled 'Wake Up', has +12V on it when the Gateway is awake. The other end of that wire is connected to pin 5 of the Instrument Cluster (32-pin connector).
If any of you have any idea, please let me know before I will remove the glovebox for the xth time.

carl viking

I have three thoughts / questions:

1. Why install an RNS-E unit in the A8? How does it physically fit? Did you make a custom plate for the dash? Impressive!
2. I retrofitted an RNS-E unit in a prior S4, and I have no recollection of it having any MOST connector at all, not even sure how you get it on the ring?
3. There used to be a forum called Audiforums.us and a very actuive RNS-E subgroup. Esp a guy called Petroldave was a rockstar of knowledge. And another called Haggisuek or sim. Both were very helpful and very, very knowledgeable. Just googled the forum and it looks pretty dead. Maybe it got moved to somewhere else?

chokboywonda

Haggis UK is on this forum

haggisuk

I am indeed here, but I have never retrofitted RSE so couldn't give you definitive advice on the subject.

Giovanni Giovino 6.0+6.0TT

[QUOTE=carl viking;24840867]

1. Why install an RNS-E unit in the A8? QUOTE]

Hello Carl,


He installed RSE not RNS-E, RSE = Rear Seat Entertainment.


.

carl viking

[QUOTE=Giovanni Giovino 6.0+6.0TT;24840903]Oh boy - fail on my side!

That said - that RNS-E forum was loaded with a number of smart people that knew the Audi entertainment systems well.

I could have sold him my system - sadly it is getting very little use. The idea of a DVD changer was cool, but in today's world the kids never end up with DVDs they like in there and for some stupid reason the car has to be turned ON to remove the cartridge, so they never do before we leave.
And with two kids the idea of having the SAME movie on both screens is a deal breaker now. Worked when they were tiny though.

carl viking

By the way - to the OP - this is not how it works (at least not for North American market). You have to have the car turned on to remove the cartridge.

silkworm

Hello,
It's me, again! Did you miss me already? Yeah, I didn't think so.

Good, now that we cleared that up, let's get to the point: remember the +12V wire that I was looking for? Well, I got news: I didn't find it.

I searched everywhere for it, including auxiliary equipment that has to be woken up by the primary equipment connected to the MOST ring (i.e. - subwoofer for AMP, SDS for radio, phone bracket for Telephone module, display for MMI, and finally, Instrument Cluster for CAN Gateway). By the way, did you know that SDS is connected to MOST ring through regular metal pins and not by optical fiber? Strange, but that's how it is.

There is not a single wire that has +12V on it when and only when the MOST ring is up and running. Everything is powered from KL30 (permanent +12V directly from battery - fused, of course).

The closest wire is the one I talked about in my earlier post - the 'wake up' wire from CAN Gateway to the Instrument cluster (yes, I removed the glovebox), but that wire has only 11V (it seems it's actually a databus) and that's still not enough for the relay to power on.

So it's time for plan B: if only I can find a relay (or something similar) that allows +12V to pass through when it detects some load on a device, so I can mount it in front of the TV tuner and if it detects a load more than 200 mA for instance, that means the tuner is awake so the relay should power on the DVD changer at that point, until the TV tuner requires less power. I know these type of relays exist, they can be found in household appliances, but I don't know if there is an equivalent for them in automotive industry.

There is also plan C : actually, what really bothers me is that the DVD changer turns off when I shut off the engine (but while the key is still in the ignition). The other equipment doesn't turn off until I actually remove the key from the ignition, so if I can find a way to power the DVD changer from the accessory bus (also called 'ignition position 1' or 'KL R'), then it may be enough for me.

I know RSE may be obsolete, but I wanted something that it's OEM and that can be controlled by the driver. I really like that almost everything in the A8 can be controlled by the driver, including passenger's seat position and interior lights for the passengers on the back. Unfortunately, the RSE version I have is only partially controlled by the driver, but I found out this only after I already mounted the system.
This RSE version supports three different images on the three screens (1 x MMI + 2 x headrests), but you need a third source for AUX-IN (the first two are TV-tuner and DVD changer). I am planning to use a tiny Intel Compute Stick for that, I already found a good HDMI - RCA converter, but it has 5 VDC power so I need to find a way to convert 12V to 5V.

Regardless of RSE presence, you can have a tablet in any car, either mounted 'on the fly' on the back of the seats, or in someone's hand or lap. I will recommend the Sony Vaio Tap 11 for this: it's large enough but still very slim, powerful enough for multimedia applications, good battery time, great display with great viewing angles, and you can also use it for internet tethering if you have a good data plan. But that's another story.

Well, the original DVD changer (Alpine DHA-S680P or 4E0088660) behaved like I said - the DVD cartridge could be removed anytime because one of the wires is connected to KL30, as per Audi electrical instructions and also Alpine installation manual. The unit I got had some issues and I bought the next version - Alpine DHA-S690P, and I don't know if it behaves the same because I didn't try that, but I suppose it is, because the power connections are exactly the same - actually it was 'plug and play'.

richard-tx

I think you should rethink the whole power for the rear seat entertainment. There is a reason why everything is powered down when the car is off. Having said that, it is possible to turn the radio on without the key being present. If it were mine, I would tap into the controlled amplifier power with a relay. It will do everything needed for the RSE. Put another way, without sound, video is pretty boring. Now it properly integrated. To convert +12 to +5 all you need is a 12v USB charging hub. Something like this:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1