Android Head Unit - Adapter for KEY1 & KEY2 for Steering wheel controls

Nuje

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I have this Android (v6) head unit, and everything's working great - backup camera, apps like Torque, even got CarPlay working with this dongle.

However, looking at the instructions, the KEY1 and KEY2 wires are there to provide steering wheel controls for the stereo (volume +/-, channel or seek up/down). From doing some reading, these are wires that can read the "analog" signal from the car steering wheel, and those apparently went away some time in the Pleistocene era.

Does anyone know what adapter we could use to get the buttons on the Mk4 MFSW to "talk" to the KEY1 / KEY2 wires on one of these stereos?
 

ToxicDoc

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There definitely is something available on the market. I just had a local radio shop do this for me last week for my '01 with the K-line communication (before canbus) when I had my Sony radio installed.
 

StevenT

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I used this adapter from Crutchfield on my recent head unit upgrade
 

Nuje

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I looked at the adapters from both PAC and Metra (Axxess ASWC-1 is their interface), but the thing with both of those is that they rely on the head unit having a wired remote input, which is in the form of a 3.5mm plug (looks same as headphone plug back when those existed on cell phones). And that 3.5mm "wired remote" input is commonplace on your brand name (Kenwood, Pioneer, JVC, etc.) head units, but not so much on these Android units.


What I need is something that has dedicated wires...although....as I type that, I realize that a headphone plug is simply a two-wire (or three if microphone is part of the headphones) connector, just in a different form factor. So, maybe (?), i can take the cord coming out of the PAC or AXXESS adapter, cut it, separate the wires, and splice those into my KEY1 / KEY2 wires.

Ordered the Metra Axxess (better price) to give it a try. ¯\_(ツ)_/¯
 

Nuje

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Update: Turns out the Axxess ASWC-1 comes with a 3.5mm to two-wire adapter, so....🤞
 

wonneber

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Interesting.
My Kenwood uses a small microphone with the 1/8 or so jack.
I used double sided tape to mount it and the GPS antenna on top of the dash just behind the inspection & registration stickers.
So far so good.
Only thing I have to find is the backup signal wire and the illumination wire.
 

Nuje

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Illumination wire: use the grey/blue stripe wire on the dimmer switch (dial) that's to the immediate left of the headlight switch (assuming you want the backlight of your display to dim; if not grab grey-purple from headlight switch.

Backup signal: There's that little red pig-tail of a wire (maybe 6") that's on either end of the video feed wire (yellow RCA plug) from the backup camera. At the camera end, just tap the wire that's powering your camera into that red wire, then splice the red wire at the other end (where you're plugging into the head unit) into your REVERSE wire on the harness.

From a thread over on Vortex:
First, GoMobileR32's DIY thread for the AVIC-D3 is a good source for finding wires.
https://forums.vwvortex.com/zerothread?id=3134807
Switched 12v is pin #1 at the headlight switch, dimmer control is #17 (grey/blue). GoMobile makes the good point that if your head unit is expecting just a non-variable signal to tell when the lights are on, you should use the grey/purple line (he doesn't give a pin number) instead. I've read some threads about people's head unit freaking out if it gets a low (dimmed) illumination signal.
Also in GoMobile's install, he shows the wire to tap for the S-contact instead of just straight 12v switched. The S-contact goes hot when you turn the key, but stays hot until you take the key out, where the 12v switched will go cold when you turn off the ignition. If you tap the S-contact line instead of switched 12v, your head until should stay on after you turn off the engine, remaining on until you pull out the key, just like the factory radio. It _should_... I make no guarantees.
You can tap the S-contact line at the steering column like he illustrates, or someone else in this subforum pointed out that line is also available at the fuse block.
https://forums.vwvortex.com/zer...75714
 
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Nuje

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...and to follow-up on my previous thoughts on the usability of the AXXESS ASWC-1, looks like it should work.

From the instruction manual:
Universal “2 or 3 wire” radio: Connect the steering wheel control wire, referred to as Key-A or SWC-1, to the Brown wire from the connector. Then connect the remaining steering wheel control wire, referred to as Key-B or SWC-2, to the Brown/White wire from the connector. If the radio comes with a third wire for ground, disregard this wire.
 

KrashDH

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Illumination wire: use the grey/blue stripe wire on the dimmer switch (dial) that's to the immediate left of the headlight switch (assuming you want the backlight of your display to dim; if not grab grey-purple from headlight switch.

Backup signal: There's that little red pig-tail of a wire (maybe 6") that's on either end of the video feed wire (yellow RCA plug) from the backup camera. At the camera end, just tap the wire that's powering your camera into that red wire, then splice the red wire at the other end (where you're plugging into the head unit) into your REVERSE wire on the harness.

From a thread over on Vortex:
If you don't want to cut into your harness, just make a wire with a female spade at the end and run it out of the backside of the tail light bulb holder at the reverse bulb... Same way you'd do the 5th brake light mod
 
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Nuje

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So, just to wrap it up, indeed, everything worked as hoped.

1. Connect wires:
Metra Axxess ASWC-1 12-wire harness (only use four wires: CAN-HI, CAN-LO, power (ACC), ground):
Pink = CAN-HI (orange/green)
Blue/Pink = CAN-LO (orange/brown)
Red = ACC power
Black = ground

ASWC-1 Female 3.5mm Adapter:
Brown = KEY1 wire on Android head unit harness
Brown/white = KEY2 on Android head unit harness

2. Turn on the car, start tapping the VOLUME UP button on the MFSW for the ASWC-1 to recognize the car.
If you get solid red LED on the ASWC-1, all's good - car's steering wheel controls have been recognized.

3. Go into STEERING WHEEL LEARN (or wording to that effect) in the Android head unit SETTINGS.
Reset to clear whatever's programmed in. Then press VOL+ in that settings screen, the press/hold VOL+ and you should get a confirmation. Do that for remaining VOL-, CH up, CH dn buttons on SW. ASWC-1 instructions say VOL+, VOL- have to stay as volume controls, but the CH+, CH- buttons can be set to be whatever you like (e.g., answer phone, mute, etc.)
 

wonneber

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Thanks for the replies.
Have all of them printed out.
Will try over next weekend or so.
 

Nuje

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As an update to this: I hadn't really driven the car much before I did all of this work, but ever since I got everything put back together, I've had some seriously bad parasitic power drain; like, with brand new battery, if I left the car sitting for a few days, it was grumpy about starting, or if it went more than a week, it was D-E-D dead!

I looked for all kinds of things, but then remembered my stereo....maybe something was drawing power there (?). Unplugged the quad-lok connector, left the car sit for a few days, and it fired right up no problem. So, it's something to do with the stereo - and I think it might be the ASWC-1 and how it's wired (it wires in to the CAN wiring - hypothesis is that it doesn't allow the CCM to go to sleep, so it's "lit up" 24/7, siphoning off electrons.

So, test #2 over the next couple days is leaving the quad-lok connected, but unplugging the ASWC-1.

Stay tuned...
 

RexNICO

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Yes, I recall if you use the Monsoon amp with and aftermarket HU, you have to move the Monsoon over to a switched 12v source or something. Too long ago to recall the details enough to be helpful, sorry.
 

kd7iwp

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@Nuje How are things working out? My sister wants CarPlay in her 2004 Jetta so I'm looking for something like this. I have an Avin Avant 4 (Android unit) in my 2001 BMW 325i and it's working really well with a CarPlay dongle. I can't seem to find more-common names for Android units of the regular double-din variety. She doesn't have steering wheel controls but I want to ensure the unit turns on/off properly so if I got the same head unit you listed, and the Metra Axxess ASWC-1 then I should be good to go? I obviously want it to get the on/off signal via CAN bus.
 

Nuje

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I did try a CarPlay dongle from CarLinkit, but it was sporadic (would work great, then I'd stop at the store or something, get back in the car, and it'd hang at starting up - not every time, but enough to be frustrating), so I just use the Android unit as a radio / bluetooth streaming device.

I did notice that with my on/off via CAN bus, it doesn't seem to let the CCM "sleep" properly - if I leave the car for a week, the battery would be weak; more than 10days and the car wouldn't start. Driving every day, no problem. I know it's a total hack, but I just put a fuse-tap into the radio fuse position - I just pull that out if I know the car's going to be sitting for a while. Plug it back in before I start (I've left it up to a month - no problems starting the car), and the stereo boots and all is good.
 

kd7iwp

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I did try a CarPlay dongle from CarLinkit, but it was sporadic (would work great, then I'd stop at the store or something, get back in the car, and it'd hang at starting up - not every time, but enough to be frustrating), so I just use the Android unit as a radio / bluetooth streaming device.

I did notice that with my on/off via CAN bus, it doesn't seem to let the CCM "sleep" properly - if I leave the car for a week, the battery would be weak; more than 10days and the car wouldn't start. Driving every day, no problem. I know it's a total hack, but I just put a fuse-tap into the radio fuse position - I just pull that out if I know the car's going to be sitting for a while. Plug it back in before I start (I've left it up to a month - no problems starting the car), and the stereo boots and all is good.
Thanks for the feedback. I have some unlabeled black CarPlay adapter for Android that uses this AutoPlay app (I got the head unit and dongle from Avin USA) in my E46 and have been fairly happy with it. Ended up getting my sister a Sony XAV-AX150 or something like that, was the cheapest CarPlay head unit that I could find in stock. Will see how it works. I got the Axess XSVI-9003-NAV adapter that hopefully doesn't keep the car awake and drain the battery. I had considered not using an adapter and just sending a switched 12v line to the head unit but figured it is nice being able to use the radio after opening a door and not having to insert a key.
 

kd7iwp

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So far everything is working great. I installed the Sony headunit and the Axess adapter. I haven't tried to measure current draw when not in use yet but functionally it does what I want, I think. When I get out of the car the stereo stays on until I lock the car with the fob but I wouldn't be surprised if the original stereo did the same since the door lock microswitches are broken on both front doors (I have new microswitches and will fix them next week) so the car doesn't know that you actually opened the door.
 

Nuje

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That's not proper behaviour of the key / radio dance. The radio should shut off when you pull the key out of the ignition; opening the door (or not) should have no impact on the functioning of the radio. So, even if the doors have bad switches, I gotta think something still isn't wired properly with your Sony stereo.
 

kd7iwp

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That's not proper behaviour of the key / radio dance. The radio should shut off when you pull the key out of the ignition; opening the door (or not) should have no impact on the functioning of the radio. So, even if the doors have bad switches, I gotta think something still isn't wired properly with your Sony stereo.
I think it’s actually working correctly. When I’ve been driving the car and remove the key it shuts off. When it seems to stay on is where I turned the key to accessory mode and turned it on, but never started the car. When I have been driving and pull the key out the doors unlock, but not when I’ve only been in accessory mode. Forgive my misunderstanding as I have not owned a VW for a few years now.
 

kd7iwp

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Nope, it doesn't usually shut the radio off when I remove the key, but it does always shut off when I remotely lock the car. I may contact Crutchfield to see if they have anything to say about the unit.
 
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