Understanding the factory CD and boot amp

[foxdie]

Hi folks, this thread is intended to piece together information from fellow club members, other enthusiast forums and personal research. It is a work in progress and will be amended as time goes on.

Part 1
As some of you are aware, a small percentage of 8G VR-4's left the factory with an upgraded in-car entertainment system which comprised of a 10-disc CD changer, 4.1 amplifier and an 8" subwoofer, all of which located in the boot. phosty took some excellent photos here (http://www.clubvr4.com/forum/showthread.php?6373-Radio-Wiring&p=241567&viewfull=1#post241567).

For those (un)lucky enough to have come into ownership of these cars, upgrading the head unit to an aftermarket model is fruitless without either installing an aftermarket 3ch/4ch amplifier or worse, running cables to all the individual speakers.

The reason for this is because (on these particular) variants of the VR-4, the speaker wires do not terminate behind the centre console like in every car, they terminate in the boot under the spare wheel cover. You can buy a Mitsubishi-to-ISO loom and it will power up the radio, however you will have no sound. I found this out the hard way recently when I tried to upgrade to a Kenwood single DIN stereo.

In these particular variants, the audio is sent separately to the amp in the boot by a 13-pin DIN connector like the following (rightmost connector);

73731

After a bit of playing about, it became clear that audio from these factory upgraded head units was being sent to the amp in the back via a 13-pin DIN cable, so out came the multimeter and I started to try and find a way to replace this unit. This is what I found;

=== This information is incomplete!! ===


Right Channel Audio
N/C
Left Channel Audio
Audio Ground
N/C
N/C
Remote amp (+12V when radio is on, GND when not)
N/C
+5V (data signal)
+5V (data signal)
Gnd (possibly for above)
N/C
+5V (data signal)

=== This information is incomplete!! ===

So the first thing I thought of was "Can I feed audio into the amp if I power it up manually?", the answer was sadly no, even though I could hear the speakers quietly clicking when I turned the amp on and off with Pin 7, nothing came out. That's when I started to think about the serial lines.

This is further reinforced by the fact that the audio coming from Pins 1, 3 & 4 was unaffected by the volume control / tone control / fader / balance. It was a constant line level output whilst the head unit was on (specifically the radio input but I imagine it would be the same for the tape).

[foxdie]

Part 2

So after the events of the first post, I started messing around to try and build a line-in cable, I had some scraps (previous 13 pin DIN male-male loom and a newly purchased 13 pin DIN socket from ebay) and one iteration of this cable (with an incorrect pin layout) resulted in mono sound (or more specifically, that hollow sound from having stereo audio with no ground, each channel cancelling out the common part of the sound (http://electronics.stackexchange.com/questions/42623/what-is-it-that-strips-vocals-from-audio-when-a-1-8-audio-jack-is-partially-unp)). What was interesting however was when I fiddled with the balance (or any of the controls) there was a rhythmic pulsing / clicking, further reinforcing the thought that there was some serial communication going back and forth between the head unit / amplifier / CD changer.

After that, I started to do some deeper research. I managed to find a nice Google hit which outlines pinouts for a similar Mitsubishi head unit from a 3000GT / GTO which is as follows;

=== This information is not applicable to our cars!! ===

73821

=== This information is not applicable to our cars!! ===

Although this closely tallies up there is at least one difference; The ACC / Remote is Pin 7 on ours and Pin 6 on the above pinout for the 3000GT head unit.

Mini-update: After picking up an oscilloscope for a good price from a friend, I definitely managed to establish the fact that there's some 5v TTL serial communication going back and forth between the head unit and the amp;

73830 73831

[foxdie]

Part 3

Okay so the research lumbers on, I started today by trying to strip the head unit down to try and identify it's manufacturer, unfortunately the screws in the side of the head unit are virtually welded in place, even with the correct size screwdriver I managed to start to strip one of the screw heads, so before I did more damage I decided to skip.

I did however take some photos where I could jam my camera phone, these are attached;

73864 73867
73865 73866

Moving on, as you can see in the later replies I built a break-out cable to let me start debugging the protocol, unfortunately I haven't yet gotten the logic analyser but I did spend a bit of time playing around with the Oscilloscope and got something meaningful from it;

73868

Ch1 was connected to (I believe) pin 9 and Ch2 was connected to pin 13. The above graphs are taken whilst turning the volume up one notch, you can see that both channels start pulsing 5 times before going quiet again. After aligning with one of the messages...

73869

and then zooming in...

73870

we can see that Ch1 has a regular pulse and Ch2 has an irregular pulse. To me, this says that Ch1 is a clock base for transmission and Ch2 is the message being transmitted.

Further digging into this protocol revealed this (https://web.archive.org/web/20050509160913/http://joerg.hohensohn.bei.t-online.de/mbus/) website (since gone offline but the Internet Archive (https://archive.org/) has a copy) which starts to describe how the transmissions work but the protocol differs (theirs focuses on the Alpine implementation of M-Bus, ours may be Pioneer at this point).

By the looks of it, we've got 8 bits being transmitted so 5 bytes, here's all of the messages in sequence;

73871 73872 73873 73874 73875

From what I can tell, the messages are as follows;

Seq / Binary / Hex / ASCII


01101111 = 0x6F = o
11100101 = 0xE5 = å
01001000 = 0x48 = H
01111101 = 0x7D = }
11001111 = 0xCF = Ï

Means nothing right now but sure it'll become clear with further investigation.

Update: I've gotten the Logic Analyser working nicely and started to export the decoded data to a Google Spreadsheet here: VR-4 Head Unit to Amp to CD Player Protocol (https://docs.google.com/spreadsheets/d/1XXM6kyK5yIIwYFQoQDgdN3qbEfHfPmww1haL2ycxHSk/edit?usp=sharing)

[foxdie]

Reserved for part 4.

[Davezj]

i had a sub in the boot of my legnum but a previous owner had done the conversion to a standard single din head unit and they had discannected the sub abd amp in the boot and just cut the speaker wires and run cable directly to the individual speakers.
i think this is the most straight forward way to do it, and if you want to connect the sub up in the boot you can run a pair wires from the head unit directly to the sub as most modern head units have a sub out connection on the back of them.
if you want to run wires from the head unit to the boot, tape the new wires to the old 13 pin din cable before you pull the old cable out, then you will pull the new wires through to the boot as the old wire comes out.

it all depends on if you want to reuse the old amp in the boot to drive the speaker, or replace it for a more modern amp.

[foxdie]

Part 2 has been added.
Davezj yep that'll be the simplest option but isn't as fun as working out a puzzle or making use of something that can still do a good job with a bit of coercing :)

[Davezj]

it is good to have a fun puzzle to solve. wish i had more info in it to help you on you way.

[Atik]

Part 2 has been added.
Davezj yep that'll be the simplest option but isn't as fun as working out a puzzle or making use of something that can still do a good job with a bit of coercing :)

Jason, you are going to end up spending days and days working this out only to end up going and doing it the easy way :p

[foxdie]

Jason, you are going to end up spending days and days working this out only to end up going and doing it the easy way :p

Well, probably yeah, but as I've only got a budget of 600 quid to spend on the car I've gotta at least try :)

[foxdie]

Updated part 2 with a couple of photos

[Davezj]

nice scope, show your waveforms, show me your waveforms.

You can't hand my waveforms.

[foxdie]

Updated to reflect pin-out updates in Part 1 and remove incorrect information in Part 2.

My car now has a working line-in by connecting some wire to pins 1, 3 and 4 above and using a bit of trickery;

I connected a stereo Bluetooth receiver and was able to play music through, unfortunately there is no 'quiet' input so we can send audio without interference. Without a cassette tape, playing Bluetooth audio with the radio input on results in the the radio being mostly muted (Bluetooth audio overrides it, doesn't well mix it as one would expect) and the CD player input doesn't take any sound feed from the head unit whatsoever.

I did find a nifty workaround though, you can trick the head unit into thinking a tape is present by doing the following;


Gently lift the tape flap
With the blunt end of a pen, gently and slowly push the tape eject mechanism (located towards the ceiling of the head unit) all the way in until it latches
Then use the pen to gently rotate the closest spindle (the bit that turns the tape) for about a second
That's it! Remove the pen slowly and enjoy

This workaround even survives the input being changed and the radio being turned off with the ignition, but is totally reversible by just pressing the eject key. Win-win :)

[Grid]

Looks like the headunit replacement is not possible unless the serial communication is understood and worked around, am I reading this right? You may want to look into acquiring a Logic for that - https://www.saleae.com/

[foxdie]

Looks like the headunit replacement is not possible unless the serial communication is understood and worked around, am I reading this right? You may want to look into acquiring a Logic for that - https://www.saleae.com/

Correct, the amp will not output any audio if you simply turn it on by setting Pin 7 high, it needs to be told what the settings are (volume, tone etc) before it will work, presumably to stop speaker popping.

As for a Logic Analyser, already got one on order (http://www.ebay.co.uk/itm/252127915256) :)

Once the protocol is captured, I'm thinking it'll be possible to build a small and cheap PCB with a microprocessor on-board to 'play back' the first init commands to turn the amp on and set the volume to maximum, then use the volume control on the new head unit to control the volume.

The only potential issue I can foresee is there's no tone nor fader / balance control, I could probably decode the entire protocol and build a replacement controller that could fit in the glasses holder or a single DIN slot without too much effort, I'm thinking of possibly using an ATTINY84 (http://42bots.com/tutorials/programming-attiny84-attiny44-with-arduino-uno/) in either case but with that many inputs / outputs I could easily build a front-end :)

[Grid]

Arduino path is probably right, easiest to jump into. It's worked for me for a few pet projects (unfinished ones... sigh). Exciting stuff! Wish I had a VR-4 amp to play with, but my Regnum came pretty much bog standard from the factory.

These are the microcontrollers I've dabbled with so far:
https://www.arduino.cc/en/Main/ArduinoBoardProMini
http://lowpowerlab.com/moteino/

This one is a cheap cheap Arduino clone to go with your Logic ;-)
http://www.aliexpress.com/item/10pcs-lot-STM32F103C8T6-ARM-STM32-Minimum-System-Development-Board-Module-For-Arduino/32277170712.html

[Davezj]

It is an interesting project but time consuming and costly when you cold buy 10m of speaker wire chop it at the head unit and run the new wire to each speaker. Could be done in about 2 hours realistically,
But I know what you are like when you get the bit between your teeth Jason .
Just keep pounding away until you get satisfaction. Lol

[foxdie]

It is an interesting project but time consuming and costly when you cold buy 10m of speaker wire chop it at the head unit and run the new wire to each speaker. Could be done in about 2 hours realistically,
But I know what you are like when you get the bit between your teeth Jason .
Just keep pounding away until you get satisfaction. Lol

I'm not really doing this for me, I'm doing it for future owners who may want to follow my steps :)




Okay okay I'm doing it for me :D

[Davezj]

sorry mate could not resist it, you have to keep your capacity at max, and dont induce any errors.

i am so funny it kills me, i get my coat.

you keep going jason, it is worth getting to the bottm of the issue. and sorting it out, i give you a great sense of achievement.

[Grid]

Dave /lol though to tell the truth this is about demystifying a rarely seen option in a car that's rare as hens teeth itself. Like I said before - exciting stuff!

[Davezj]

Just thought I would throw this one out there, is the protocol likely to be CANBUS or at least an early form of it.

[Davezj]

Might this be of help

http://www.installdr.com/harnesses/Mitsubishi-Wiring.pdf

Or this

http://www.the12volt.com/installbay/forum_postsm.asp?tid=57689

I can't view it properly on my phone

[Grid]

I have a feeling Mitsubishi just took something off the shelf and branded it. The volumes were too low to justify developing it in house. The Pioneer "P-Bus" has remarkably similar sounding line names to the GTO picture Jason posted:

73841

http://en.calameo.com/read/0012203441b1510fb9c89

Would be good to open up the amp or headunit and check if there are any Pioneer markings inside. Or at least to see if the main CPU marking could be read. That could help point things in the right direction.

[Davezj]

When i found my amp under the floor in the boot, I ended up throwing it away after trying to give it away to anyone who wanted it.
Getting rid of it enabled me to fit a left hand side storage box. And more under floor storage is always nice.
I still have the 13 pin din cable and the output cable that was connected to the amp in the car.
If you trash yours trying to get it to work , you can have it if you want it.

[Davezj]

Just out of interest did the uk spec cars come with the same amp option?
The reason I ask is because there is a full uk spec galant wiring schematic in the library so it would have the audio wiring in there as well.
Worth a look.
Search on username davcom1 and wiring. The original hosting site is long gone but I believe one of the other members is hosting it for the site now.
It is a 95mb PDF so it is not easy to upload to the library.

here is one place
http://www.clubvr4.com/forum/showthread.php?39333-Full-Galant-Legnum-Wiring-Manual-HERE!&p=744608&viewfull=1#post744608

here is another place
http://www.clubvr4.com/forum/showthread.php?39333-Full-Galant-Legnum-Wiring-Manual-HERE!&p=758511&viewfull=1#post758511

[foxdie]

Grid the pin layout is similar but slightly off. I'll pull it apart tomorrow.
Davezj I checked out the electrical diagram and sadly it doesn't cover the subwoofer, CD player or amp but good thinking regardless :)

Just to add a tiny bit more news, I've got a 13-pin DIN extension cable that I'm gonna chop and fit a breakout board to be able to access the pins easier. Sadly the logic analyser didn't arrive in time, that'll be next week.

[Grid]

More digging

http://www.mictronics.de/projects/cdc-protocols/

73842

In fact people have made hard-drive mp3 based CD-changer emulators /lol

http://vitat.spb.ru/index.php/cat,21.html

[foxdie]

Thanks Grid, will update tomorrow with my findings :)

[foxdie]

Okay didn't get to take the head unit apart today (weather not great) but I did manage to find time to build this;

73843 73844 73845

That's a 13-pin DIN extension cable with a break-out / interruption jumper set and a line-in socket :)

[Grid]

Nice systematic approach, build the tools first, do research :thumbsup:

I'm way too chaotic to plan ahead like that /lol

[foxdie]

Nice systematic approach, build the tools first, do research :thumbsup:

I'm way too chaotic to plan ahead like that /lol

I'm not normally this organised ;)

Ps. Part 3 is updated :)

[Davezj]

CAN-BUS protocol explained

https://en.wikipedia.org/wiki/CAN_bus

[foxdie]

CAN-BUS protocol explained

https://en.wikipedia.org/wiki/CAN_bus

I don't think CAN BUS is relevant here, CAN doesn't have a clock line, this seemingly does and pre-dates CAN implementations in cars by about 10 years.

I've also got a lot of experience with CAN (specifically GMLAN, see below links) so admittedly it was one of my first suspicions :) (great minds think alike)

GMLAN Library for MBED (https://developer.mbed.org/users/foxdie/code/GMLAN/)
GMLAN Bible (http://is.gd/gmlanbible)

[Davezj]

Fair enough, I did read the can bus description and I thought it didn't sit right with what you described as seeing, but it was only when you said that you data was clocked it clicked.
Yes I have looked at screen shots you uploaded but it still didn't click until now.
Doh!

[Davezj]

Are you reading the bits round the correct way, it seems as you are read 0v as logic 1 and 5v as logic 0, from the screen shots in update 3. Is that correct for this application.

[foxdie]

Heh, I don't know :) I just based it on the fact the clock line goes low to signal a read.

Inverted they would read as follows (chars aren't standard ASCII);

Seq / Binary / Hex


10010000 = 0x90
00011010 = 0x1A
10110111 = 0xB7
10000010 = 0x82
11110000 = 0x30

[foxdie]

Logic analyser is here, well worth a fiver (http://www.ebay.co.uk/itm/252127915256) :thumbsup:

73882

Software from Saleae (http://support.saleae.com/hc/en-us/articles/201589175) has a built-in protocol inspector too, may help decode it :)

[Davezj]

Heh, I don't know :) I just based it on the fact the clock line goes low to signal a read.

Inverted they would read as follows (chars aren't standard ASCII);

Seq / Binary / Hex


10010000 = 0x90
00011010 = 0x1A
10110111 = 0xB7
10000010 = 0x82
11110000 = 0x30


ok, that make is always an option, what type of probe are you using to connect to the cale is it home made or a proper scope probe. just woundering if you have pos and neg swapped on the probe.
as having a high signal that goes low to signify a clock not something i have come across as the normal way round. but i have not played with this sort of stuff for years so i am just thinking out loud, and not having the stuff infront of me is a bit of a disadvantage. lol.

[Davezj]

Logic analyser is here, well worth a fiver (http://www.ebay.co.uk/itm/252127915256) :thumbsup:

73882

Software from Saleae (http://support.saleae.com/hc/en-us/articles/201589175) has a built-in protocol inspector too, may help decode it :)

what type of probe/cable are you using to connect to the laptop/smartphone.
that logic analyser software looks great for the money, £5 that is amazing.

it looks that good i just bought one with some hook up clips.

[Grid]

what type of probe/cable are you using to connect to the laptop/smartphone.
that logic analyser software looks great for the money, £5 that is amazing.

it looks that good i just bought one with some hook up clips.

Jason bought a Chinese knockoff of the Saleae Logic analyzer. It's not quite there but it works almost like the real thing, and it is compatible with their official software...

[foxdie]

I still maintain it's excellent value, works perfectly with the software, although I haven't processed them yet I've grabbed some samples of various things here;

amp protocol samples (https://www.dropbox.com/sh/y26tialh24n5z0k/AABD1clJLJXwadgvO7vRUZ8Ra?dl=0)

The channels were as follows;


Channel 0 = Pin 9
Channel 1 = Pin 10
Channel 2 = Pin 11
Channel 3 = Pin 13

You'll need the free Saleae Logic program from above to open the files :thumbsup:

Ps. Yes the probes were the correct polarity Dave, the probes are genuine Tek ones with a clear ground crocodile clip on each one :)

[foxdie]

Just a last note on those previous samples, I have a gut feeling the sample rate for the Logic Analyser was too low, I'm gonna redo them at a higher sample rate soon to be absolutely sure.

[Davezj]

i can view you logs looks interesting.

[foxdie]

I'm almost certainly convinced the sample rate on the LA (Logic Analyser) was too low now, it was done at 125k samples/sec whereas the TekScope was 500k samples/sec.

I'll redo the measurements tomorrow morning when I park up at work at 1M samples/sec to be sure.

[foxdie]

Turns out I was right, have taken new samples (and of more activities) at a much higher sample rate, see the link in the previous posts :)

[foxdie]

Have updated Part 3 with a link to a spreadsheet where I'm decoding the data :)

[Davezj]

Jason if you want to reallocate some of my first post in this thread to make the thread flow better at the beginning feel free, you would have to get one the mods to do it thought,
or post up what you want to say in a later post and I will copy and past it in the appropriate post.

just remember being able to editing posts only lasts for 2 months.

let me know

[foxdie]

Yeah you're right, I'm reserving Part 4 for the absolute information once it's all decoded and understood :)

A friend of mine in Oz who is a smart cookie when it comes to patterns has already spotted early on that a lot of requests that go over the bus are repeated but only a couple of bits change depending on the actual function.

Hopefully more tonight :)

[ersanalamin]

Jason my MMCS comes with no stock subs and amps but do has stock CD changer. If i bought the stock amps and 8 inch sub, do you think it will work with current MMCS set up? you might interested in this guy project https://sites.google.com/site/udcaus/about-udc

[Piers1989]

Really interesting thread!

The Legnum I just bought DOES have the factory upgraded sound system and Sub - unfortunately either the amp or speakers are all but blown to pieces!

I'll keep a close eye on this thread!

Does the Head Unit continue to output audio if the amp isn't on the other end? I was thinking of leaving the head unit intact and installing an after market amp in the boot and I could cannibalize the DIN cable for that.

[foxdie]

Does the Head Unit continue to output audio if the amp isn't on the other end? I was thinking of leaving the head unit intact and installing an after market amp in the boot and I could cannibalize the DIN cable for that.

Hi Piers,

The head unit outputs a line-level signal to the amp for both the cassette tape and radio inputs. This does not change with volume, the head unit and amp have a serial link going back and forth exchanging data, it's the amp that controls the volume.

My research into this stalled when I figured out it was easier just to keep the stock head unit and patch in a Bluetooth Stereo receiver (tucked behind the head unit) to the line-level link to the amp, then trick the head unit into thinking a tapes inserted by pushing a pen against the metal lever inside and spinning one of the capstans a little to make it think there's a tape inserted. It remembers one is inserted indefinitely (or at least until the battery is disconnected) :)

I have a head unit to fit too but to use an aftermarket head unit with the stock amp will require using a microprocessor to tell the amp the power on / off / adjust volume / tone / balance etc.

Alternatively, and possibly easier, would be to re-use the DIN wiring (with a pin-out similar to stock to prevent shorting) to send a line-out and remote amp signal from an aftermarket head unit to a 5/6 channel aftermarket amp in the boot. You can either butcher the wiring or make up adapter cables to be able to return everything to stock.

If your subwoofer is blown, I have 1 repair kit remaining, I can either repair it for you (£50) or post you the repair kit (£10) and you do it yourself.

[Piers1989]

Thanks for your detailed reply!

I did read that it was a line level link in the earlier posts but didn't take that into consideration with the idea of a non factory amp. I already have a Alpine PDX-V9 (http://www.alpine.co.uk/p/Products/pdx-amplifiers31/pdx-v9) and a JL Cleansweep (http://www.jlaudio.co.uk/cl441dsp-car-audio-oem-integration-98110).

Does the factory amp tend to die? I could use the Cleansweep to take the amplified speaker output, smooth it out and feed that to my alpine amp (These pieces of kit were left in my 335i by its previous owner for the same effective purpose). Providing the popping and half the speakers not working are not because the amp is fried at least!

Thanks for your offer on the Subwoofer. Do you know the size / spec for it off the top of your head? I was going to upgrade this too but if the factory unit is decent repairing it may be an option.

[Piers1989]

You guys dont have a pin out for the rear amp do you or know where I could get one? Am I right in that the door speaker unit and the tweeter aren't run from a crossover - they are sent separate signals from the amp?

I tested it with a home cinema centre speaker (dual mids and 1 tweeter) and plugged into the main speaker output it seemed to lack punch, but plugged into the tweeter output it sounded like a full range signal. I would have expected everything other than high frequencies to be cut off but it seemed full range?

I've started stripping down stuff for investigation. All my speakers and sub are wrecked but I think i am going to replace them all.

The drivers side tweeter has a damaged connection in the door somewhere.

I'll make a full thread with writeup for anyone else but for now I just need to know where to take a full range output from for my CleanSweep!

[foxdie]

Thanks for your offer on the Subwoofer. Do you know the size / spec for it off the top of your head? I was going to upgrade this too but if the factory unit is decent repairing it may be an option.

It's a 8" hole but you may need to drill new holes to get another sub to fit. You'll need to get a free air sub too.


You guys dont have a pin out for the rear amp do you or know where I could get one?

74680

[Piers1989]

That's great! I thought I had seen one but I couldn't find it. I swear it was linked in this thread earlier but I checked twice!

More info to follow :)

[ersanalamin]

Part 2

So after the events of the first post, I started messing around to try and build a line-in cable, I had some scraps (previous 13 pin DIN male-male loom and a newly purchased 13 pin DIN socket from ebay) and one iteration of this cable (with an incorrect pin layout) resulted in mono sound (or more specifically, that hollow sound from having stereo audio with no ground, each channel cancelling out the common part of the sound (http://electronics.stackexchange.com/questions/42623/what-is-it-that-strips-vocals-from-audio-when-a-1-8-audio-jack-is-partially-unp)). What was interesting however was when I fiddled with the balance (or any of the controls) there was a rhythmic pulsing / clicking, further reinforcing the thought that there was some serial communication going back and forth between the head unit / amplifier / CD changer.

After that, I started to do some deeper research. I managed to find a nice Google hit which outlines pinouts for a similar Mitsubishi head unit from a 3000GT / GTO which is as follows;

=== This information is not applicable to our cars!! ===

73821

=== This information is not applicable to our cars!! ===

Although this closely tallies up there is at least one difference; The ACC / Remote is Pin 7 on ours and Pin 6 on the above pinout for the 3000GT head unit.

Mini-update: After picking up an oscilloscope for a good price from a friend, I definitely managed to establish the fact that there's some 5v TTL serial communication going back and forth between the head unit and the amp;

73830 73831

Hi Jason.
coz
Sorry to wake this old thread up. I think I need your help. I am still running Face lift MMCS system in my Galant. And now the stock 10 cd stacker in the boot stop working, said Error 03 on monitor (mechanical problem) but I think that cd changer need new laser optic replacement. So far I dont know what kinda laser optic replacement needed and where to buy it, maybe yu guys in this forum can inform me, I am trying to keep MMCS system as long as possible until it broken beyond repair.

as alternative solution I bought chinesse made Digital Music Changer as virtual/digital cd stacker replacement even know i doubt they support stock Galant cd changer din coonector pin out. Its Yatour YT-M06 Model, Supplied with 13 pin Din Connector compatible with Hyundai Head unit on 2005-2009 Sonata，2005-2009 Tucson，2003-2006 SantaFe，2003-2008 Coupe 2005-2009 Accent，2003-2004 MAXIMA，2004-2009 CERATO GLS(with MP3 function)

https://www.aliexpress.com/item/32977670680.html?spm=a2g0s.9042311.0.0.27424c4dWkH kPj

Its very hard for me to get info on Hyundai 13 pin DIN connector Head unit pin out. In my MMCS head unit there is 13 to 8 pin DIN din connector converter cable.

Later on I think Mitsubishi and Volvo use the same cd stacker, to make things easier I bought Yatour Serial cable compatible with Volvo head unit protocol but still wont work with factory MMCS Head unit. I Also still cant find correct info on volvo on 8 pin DIN connector Pin out.

https://www.aliexpress.com/item/32836405614.html?spm=a2g0s.9042311.0.0.27424c4dWkH kPj

both Yatour 13 and 8 pin din connector not compatible with MMCS Head unit, but should work. I inted to use yatour serial cable for volvo, so I bought locally, Male and female 8 Din connector for conversion.

Can you help me indetify Mitsi and volvo 8 pin cd changer din connector pin out? is it possible to match? It would be really nice if yatour working on Mitsu MMCS head unit otherwise its about time to dump MMCS system once and for all and get 10 inch 2 DIN android head unit he he he