Hello,
some days ago i did a terrible mistake and i joined the can-rx cable(which connects the canbus decoder with the head-unit) with the swc controls cable (from the head-unit side, NOT from the car side.) After that the head-unit never powers off. It stays always on and also all the canbus commands dont work at all, like the ILL command or the reverse camera mode which was automatic.
In ford mondeo there are no ILL or ACC cables coming to the ford quadlock connector.The reverse camera image activates though canbus command as the reverse activation cable connects to the canbus decoder. All these commands come through canbus communications.
So my assumption is that either i made damage to the head-unit can-rx input or to the canbus decoder.
I have noticed three things:
1) All the head-unit functions including flashing the mcu and flashing the system-rom work ok! I read that can-rx and can-tx connect directly to the mcu so with no fried mcu on the head-unit i think that the damaged canbus scenario is more possible.
2)The canbus decoder outputs constanlty 12-14 volts on ACC cable even when the car ignition is off. That is why the head-unit never powers off. Also when i enable the headlights the ILL cable has 0 volts which is sadly expected as the ILL (dimmind of the screen and leds illumination on the head-unit) does not work.
I also gave 12 volts from my power supply to the canbus decoder with nothing connected on it and i checked the ACC cable with multimeter. The voltage was 12 volts as with my previous tests at the car where everything were connected together.
3)And one last thing i want to mention is that after all these i checked with my original sony radio that came with the car and everything is working fine including ACC and ILL so for sure there is no damage to the car side.
So i want your knowledge please.
Do you think that is it a faulty canbus decoder? Is it normal for the ACC pin on the canbus decoder to be 12 volts when there is nothing connected to it?
Does the canbus send commands to the canbus decoder through CanH and CanL for the ACC pin to be 0 volts so that is why it is always 12 volts in the first place when disconnected from the head-unit?
And if the ACC should be 0 volts where should i check for damage on the canbus decoder? Because i checked the capacitors and all seem ok. Also i cant find any obvious short on the circuit. Maybe it is the Nation N32L406 that got damaged?
Thanks in advance!
Related
Hi
I'm hoping you can help, I don't have much hair left to pull out!
I have an Audi TT 2003 and bought a VW Passat android 4.4 head unit.
The head unit uses canbus system to turn on
I connected the stereo to check operation and everything seemed fine.
After fitting (which took an age) discovered that stereo turns off after ten mins. I have to remove key, open and close the door then put key back in then stereo powers up again for ten mins. If I remove the key before ten mins and get out, stereo powers down.
Any ideas?
Peterbrid said:
Hi
I'm hoping you can help, I don't have much hair left to pull out!
I have an Audi TT 2003 and bought a VW Passat android 4.4 head unit.
The head unit uses canbus system to turn on
I connected the stereo to check operation and everything seemed fine.
After fitting (which took an age) discovered that stereo turns off after ten mins. I have to remove key, open and close the door then put key back in then stereo powers up again for ten mins. If I remove the key before ten mins and get out, stereo powers down.
Any ideas?
Click to expand...
Click to collapse
Maybe the canbus decoder from Passat it's not compatible with the Audi TT, but you can cut red wire from canbus decoder and connect directly to acc signal (12v when switch is in ACC and ON position)
All other function from canbus decoder are fine? (lights, reverse, door info, a/c info, etc)
Thanks for the reply.
There is no external canbus decoder. The canbus wires connect directly to the head unit so it must be an internal decoder.
I was thinking there may be a difference between canbus systems. They are both VAG group systems but two years different, car 2003 head unit for a 2005. Was canbus updated in this period? This is the nuclear option as it means I'll have to rip it out and start again (I have tried a canbus unit with external decoder just to see what happens-same thing just comes on for ten mins)
However, there has to be some communication as HU turns on with signal from canbus and will turn off if u remove the key (before ten mins). Also the other functions work, fuel guage etc
Peterbrid said:
Thanks for the reply.
There is no external canbus decoder. The canbus wires connect directly to the head unit so it must be an internal decoder.
I was thinking there may be a difference between canbus systems. They are both VAG group systems but two years different, car 2003 head unit for a 2005. Was canbus updated in this period? This is the nuclear option as it means I'll have to rip it out and start again (I have tried a canbus unit with external decoder just to see what happens-same thing just comes on for ten mins)
However, there has to be some communication as HU turns on with signal from canbus and will turn off if u remove the key (before ten mins). Also the other functions work, fuel guage etc
Click to expand...
Click to collapse
That's a trouble, do you open head unit to see how is inside? Maybe you can made the mod internally.
Thank you for the reply
That's what I was thinking, but I'm a little bit worried about opening it up. I don't have much experience with pcbs.
So my questions are:-
1) If I open up the canbus bypass box (from another stereo) will the pcb inside be broadly similar to the one inside the HU, giving me a rough plan as to what to look for re:- wiring and live etc
2) the switched live from a canbus bypass box 12v (as previous post said can just bypass with a switched live), is it likely to be same inside HU or will it be stepped down to 5v (should I just buy a multimeter)
Peterbrid said:
Thank you for the reply
That's what I was thinking, but I'm a little bit worried about opening it up. I don't have much experience with pcbs.
So my questions are:-
1) If I open up the canbus bypass box (from another stereo) will the pcb inside be broadly similar to the one inside the HU, giving me a rough plan as to what to look for re:- wiring and live etc
2) the switched live from a canbus bypass box 12v (as previous post said can just bypass with a switched live), is it likely to be same inside HU or will it be stepped down to 5v (should I just buy a multimeter)
Click to expand...
Click to collapse
1.- I have not idea, I never see inside of a unit with internal canbus decoder. You can open your unit and take some pictures maybe I can help you, also take pictures of the main harness of your unit.
2.- For a external canbus units just cut red wire from canbus decoder to head unit and connect the red wire from the side of head unit to 12v switched.
I will post some pics
And thanks again for the help
Hi,
I finally bought this universal SWC unit from aliexpress: https://nl.aliexpress.com/item/Car-...574.html?spm=a2g0s.9042311.0.0.2f4f4c4d3Pq2pc
I repeated this Boyka video, so I'm pretty sure that I did everything correct.
My unit originally has a CANbus as I have a Skoda.
I removed the CANbus when I got the unit (because I don't want it anyway) , connected it again 2 months ago (let's give it a shot), and now for the SWC I removed it again (as I know the CANbus "takes over" when it comes to SWC).
I disconnected the brown key1, the pink key2 and the GND wire from the little CANbus adapter connector.
From the the SQC receiving box to the Joying, I connected ACC to ACC, key1 to brown, key2 to pink, GND to GND.
In the steering wheel screen nothing works when I push buttons on the small unit or on the screen, be it long or short. The 6 fields in the top of the screen only quickly alternate between 254-255 (see attached IMG_20181020_145152172.jpg).
So then I connected my multimeter (set on 20V) as well. I connected the RED additionally to the key1 and the BLACK additionally to the GND.
I now read 5.3V source voltage. When I push buttons to close the loop, the voltage drops for a number of keys to, for example, 0.8V or 1.3V or 2.8V. Some buttons don't react.
When I connect the RED additionally to the key2, the source voltage is again 5.3V. Now the other keys show values like 1.3V or 2.8V when pressed.
Obviously the little universal unit works and it obviously needs both key1 and key2 wires.
As said, I have the CANbus disconnected and in the CARsettings I have set the CANbus settings to NULL.
What is wrong, or what am I doing wrong?
(Note: I repeated this on my Sofia unit with the exact same results: zero, that is).
surfer63 said:
Hi,
I finally bought this universal SWC unit from aliexpress: https://nl.aliexpress.com/item/Car-...574.html?spm=a2g0s.9042311.0.0.2f4f4c4d3Pq2pc
I repeated this Boyka video, so I'm pretty sure that I did everything correct.
My unit originally has a CANbus as I have a Skoda.
I removed the CANbus when I got the unit (because I don't want it anyway) , connected it again 2 months ago (let's give it a shot), and now for the SWC I removed it again (as I know the CANbus "takes over" when it comes to SWC).
I disconnected the brown key1, the pink key2 and the GND wire from the little CANbus adapter connector.
From the the SQC receiving box to the Joying, I connected ACC to ACC, key1 to brown, key2 to pink, GND to GND.
In the steering wheel screen nothing works when I push buttons on the small unit or on the screen, be it long or short. The 6 fields in the top of the screen only quickly alternate between 254-255 (see attached IMG_20181020_145152172.jpg).
So then I connected my multimeter (set on 20V) as well. I connected the RED additionally to the key1 and the BLACK additionally to the GND.
I now read 5.3V source voltage. When I push buttons to close the loop, the voltage drops for a number of keys to, for example, 0.8V or 1.3V or 2.8V. Some buttons don't react.
When I connect the RED additionally to the key2, the source voltage is again 5.3V. Now the other keys show values like 1.3V or 2.8V when pressed.
Obviously the little universal unit works and it obviously needs both key1 and key2 wires.
As said, I have the CANbus disconnected and in the CARsettings I have set the CANbus settings to NULL.
What is wrong, or what am I doing wrong?
(Note: I repeated this on my Sofia unit with the exact same results: zero, that is).
Click to expand...
Click to collapse
I bought one of these for my Joying Sofia system, one made for VWs, as I have a Passat. I had the exact same experience as you, right down to measuring the voltages and seeing them change.
Step back to my previous sysyem, an Xtrons that I bought a universal steering wheel mounted wireless controller, and it worked flawlessly. The Xtrons was also made specifically fow VWs, but the generic controller worked fine. I tried it with the VW-centric Joying Sofia and went through the testing discussed previously.
I contacted Joying Support and was told that the system itself would only respond to the resistance from the VW Can Bus and unless I had that I was out if luck.
markmorto said:
I contacted Joying Support and was told that the system itself would only respond to the resistance from the VW Can Bus and unless I had that I was out if luck.
Click to expand...
Click to collapse
Thanks for your reply.
Did Joying say anything about when you remove the CAN bus adapter? Should it somehow work in that case? Because I first disconnected the brown/pink from the Joying CANbus connector and also removed the entire JY CANbus itself.
Anyway, I will check again. I thought that the brown and pink key1 and key2 wires were leading, but obviously that's not true.
The green (CAN/L) and black/green(CAN/H) wire coming from the Skoda (in my case) ISO adapter are leading into the JY CAN bus. The pink/brown then come again from the JY CANbus and lead to the unit.
So I will try to connect the key1/key2 wires to the green and black/green wire. But maybe I need to ground the CAN/L wire and connect one or both key1/key2 wires to the CAN/H wire.
(Although in one of the Joying diagrams, the green and green/black are for the Left Rear speaker, but that does not comply with my Skoda ISO adapter. confusing.)
Of course it can also mean that the JY CANbus expects a digital CANbus signal instead of an analog resistive signal, in which case it will not work at all, not without an analog to digital converter at least.
To be continued.
surfer63 said:
Thanks for your reply.
Did Joying say anything about when you remove the CAN bus adapter? Should it somehow work in that case?
Click to expand...
Click to collapse
The way they made it sound, the stereo itself only responded to CAN bus signals. The reply was a little strange in that it mentioned 'resistor values that match original VW'. I don't know if other head units have this problem, but am a little frustrated that I lost this functionality that I had with a "cheaper" Chinese head unit.
markmorto said:
The way they made it sound, the stereo itself only responded to CAN bus signals. The reply was a little strange in that it mentioned 'resistor values that match original VW'. I don't know if other head units have this problem, but am a little frustrated that I lost this functionality that I had with a "cheaper" Chinese head unit.
Click to expand...
Click to collapse
It is also very weird.
I checked the Boyka video (https://www.youtube.com/watch?v=odnEb-1b310) where he is in a VW, using a Joying unit with a CAN bus where he simply soldered/connected the key1/key2 wires to the brown and pink. Why does that work? It is a Sofia like you have and like I still have on the bench currently doing my tests on.
surfer63 said:
It is also very weird.
I checked the Boyka video (https://www.youtube.com/watch?v=odnEb-1b310) where he is in a VW, using a Joying unit with a CAN bus where he simply soldered/connected the key1/key2 wires to the brown and pink. Why does that work? It is a Sofia like you have and like I still have on the bench currently doing my tests on.
Click to expand...
Click to collapse
I had some more mail exchange with Joying. The VW models have a different motherboard with different connections. The unit in the video is actually a universal model just connected to display the working of a universal SWC with a universal Joying unit.
So maybe I should try to use some "universal analog/CAN-bus steering wheel converter" and connect the SWC to the converter, and then connect the converter to the CAN/H, CAN/L connectors of the Joying ISO adapter.
But I'm already tired of it. I wanted a simple way to try and maybe do some test work for XFytTweaker.
Hello.
Just got my joying head unit. Joying told me it vas plug and play with my vw transporter t5.1 2013.
It has canbus and i got the canbus adapter.
Connected everything as the instruction was and it would not start up. Connected the acc after removing the canbus box. Poow.. it starts up right away. But it never shuts down after removing the key. So the problem is that it either stays on al the time. Or it never starts when the canbus is Connected. As the instructions says.
Other info.
Oem bluetooth
Mfd display
Measured my acc wire and it has constant 12v.
bjornthans said:
Hello.
Just got my joying head unit. Joying told me it vas plug and play with my vw transporter t5.1 2013.
It has canbus and i got the canbus adapter.
Connected everything as the instruction was and it would not start up. Connected the acc after removing the canbus box. Poow.. it starts up right away. But it never shuts down after removing the key. So the problem is that it either stays on al the time. Or it never starts when the canbus is Connected. As the instructions says.
Other info.
Oem bluetooth
Mfd display
Measured my acc wire and it has constant 12v.
Click to expand...
Click to collapse
Yes, It sometimes happens on VAG cars. I have that too on my Skoda. I wrote a post/document for it.
https://drive.google.com/open?id=0B4J3kKZoV78-Wk1CdVVwVlJmd0E
There are harnesses from Joying where the ACC cable needs to be disconnected, when operated in a CAN vehicle. This should be documented on a small sheet coming with the unit. You don't need to cut wires, the cable is prepared already with plugs so that you can easily disconnect and reconnect.
Update.
Joying sent me 2 new canbus adapter with dhl. the unit is turning on/off as i should.
great service by joying.
Hello All
I have a 2003 Audi TT MK1 (please don't hold it against me) which did not come with the bose system
I am in the process of doing a double din conversion and purchased a housing made for the TT that accepts VW Golf Mk V headunits.
I decided to purchase the Xtrons PSD80MTVL
Now this came with a power lead with a canbus decoder and I can't get it to turn on and need some help.
Sorry I can't post links yet but on the power harness there is no pin for the acc (ignition switch)
Looking for ideas on how to power the unit
1. does the canbus decoder need to be fitted ? I don't need any information from the vehicle to be sent to the headunit or vice versa
2. does both the yellow constant 12v and the red ignition live wires need to connected to the headunit - If so how
Any ideas/suggestions would be very much appreciated
Thanks
If I unplug the Canbus Decoder and connect the acc to the red wire in the canbus decoder plug ?
Would this power on the headunit ?
Hi professionals. Thanks for reading my plea for help. I have a 2005 SLK 200 R171. I recently decided to change my player from the usual audio 20 with cd changer to this Erisin Android PX5 head unit i got off aliexpress. When i received it, i noticed that the harness supplied with the player did not fit my car. Hence i opted to buy a Dynavin harness which by pictures the harness fitted my original plug but the cable attaching to my headunit did not. So i did my rewiring myself. Followed the usual colour and power and got the headunit powered up. However i noticed the can bus is fed with one constant wire, one ground wire, and both the can high and can low cables from the car. And there are 3 cables that goes from the canbus unit to the headunit i.e. brown for reverse, red for acc, orange for illumination. I have 2 more wires with a small harness (White and white/black stripe wire) that does not have an input to anywhere (I believe that Is the canbus high and low to the headunit) and a blue wire. On my headunit harness, according to the wiring diagram attached with the player, there is only one wire going to the can low socket and the can high is empty. Hence i attached my can low from the headunit to a blue wire from the canbus and noticed my steering wheel controls work (volume buttons and +/- track). However, the display on my dash says audio off. Also my rear view camera goes on and off (I looped the trigger wire to the reverse brown wire that exits the canbus and goes to the headunit reverse). I will try an attach a video. Does anyone know if i have made a mistake in the wiring? And does anyone have a wiring diagram for the can bus decoder (brown semi transparent box)?
Any help is very very much appreciated. Thanks tonnes.
My issue link
vimeo dot com slash 462084336
( sorry wasnt allowed to post a link)
Hello Haven,
Did you ever receive an answer? I am having a similar issue. I bought an android head unit with can bus decoder. Almost all the wiring harnesses were wrong and I had to rewire myself. the chinese supplier did not provide any wiring diagrams or pinouts, (claims they do not have any). I finally got my reverse camera, sound, and steering wheel controls working. (all come directly into head unit. The can bus decoder does not seem to be connected to the can H and Can L from the vehicle. I have the same 3 wires from can bus decoder box to android head unit. I am certain based on the other wire harnesses received that the wiring from car to can bus decoder is wrong. Can you tell me what two pins the Can H and Can L are fed to on your decoder box?