Steering Wheel buttons

[JIN]

Hi guys.

I've been reading some threads about steering wheels buttons with headunit matters.

Now I am confusing because of the Display button.

What I know, from this forum, is the display button is connected to headunit.

So, if I change the headunit with aftermarket one, the display button does not work at all?

Simply I don't care about volume and seek buttons but I really do need the display button because of the trip computer and fuel consumption digital metre stuffs.

I am going to install the aftermarket dvd player on this friday or saturday and I saw the thread about display button which is embarassing me.

Can anyone give me the clear and simple answer about it?

Thanks for your help in advance.

[dannywss]

from my memory, no one who is using an aftermarket HU(other than the one bought from ebay) can still use their display button... tracking the display button's wire, it leads back to the HU.. weird..

[jzt]

you could buy a steering wheel control adapator which allows you to use your buttons and aftermarket headunit.

just ask any car audio place they should sell them, price is around 270-300ish or so :)

[dannywss]

i think people are more worried about the display button, rather than the volume control and stuff..

[AcoustiK]

from my memory, no one who is using an aftermarket HU(other than the one bought from ebay) can still use their display button... tracking the display button's wire, it leads back to the HU.. weird..

Nope I got the display to work, you can bypass the HU, the HU doesnt control the display, so look for a orphan wiring that is neither power, antenna or speakers and bingo.

[DJKOR]

from my memory, no one who is using an aftermarket HU(other than the one bought from ebay) can still use their display button... tracking the display button's wire, it leads back to the HU.. weird..

Nope I got the display to work, you can bypass the HU, the HU doesnt control the display, so look for a orphan wiring that is neither power, antenna or speakers and bingo.

Would you be able to explain just a little bit more on how you got your DISP button to work? This would be in regards to having an aftermarket head unit right? Because in the wiring harness for the stereo, there is a connector that looks like this:

When that is disconnected from the stock head unit, the DISP button on the steering wheel loses all functionality. Doing some tests, I found that the DISP button actually integrates with the steering wheel stereo controls on the same bus. So if you had a simple solution to that, please let us know. That knowledge would be quite valuable for anyone planning to put a aftermarket head unit in.

[Kmg]

From what I read in Camry service manual in the sticky post Navigation system page NS-162, the steering pad switch assembly is slightly different with Aurion's. Since the aftermarket head unit is designed for Camry, it is not surprising that display button won't work. Can anyone upload a copy of Aurion service manual to see the wiring setting of Aurion's steering pad switch assembly?

[dannywss]

from my memory, no one who is using an aftermarket HU(other than the one bought from ebay) can still use their display button... tracking the display button's wire, it leads back to the HU.. weird..

Nope I got the display to work, you can bypass the HU, the HU doesnt control the display, so look for a orphan wiring that is neither power, antenna or speakers and bingo.

explain please... this makes the audio shop who done my installation looks damn stupid.. coz they were playing with the original HU and that display button for quite a while.. <_<

[JIN]

you could buy a steering wheel control adapator which allows you to use your buttons and aftermarket headunit.

just ask any car audio place they should sell them, price is around 270-300ish or so :)

I've been thinking that one but I don't think it makes the display button working.

All I need is display button and I don't worry about mode, volume and seeking buttons.

[JIN]

from my memory, no one who is using an aftermarket HU(other than the one bought from ebay) can still use their display button... tracking the display button's wire, it leads back to the HU.. weird..

Nope I got the display to work, you can bypass the HU, the HU doesnt control the display, so look for a orphan wiring that is neither power, antenna or speakers and bingo.

Can you please explain?

I was thinking to connect that cable with other cable such as ground? cos it looks like nothing with HU.

But I am just worrying about if I connect it with wrong one and the display is f**ked.

Which cable (which colour?) did you hook it up to?

[JIN]

From what I read in Camry service manual in the sticky post Navigation system page NS-162, the steering pad switch assembly is slightly different with Aurion's. Since the aftermarket head unit is designed for Camry, it is not surprising that display button won't work. Can anyone upload a copy of Aurion service manual to see the wiring setting of Aurion's steering pad switch assembly?

I think you better have a look at the Electric wiring diagram.

The manual is on this forum one of the pinned at the top.

It gives you all the details of eclectric wiring diagram of GSV40 Series and ACV40 Series.

The GSV40 is aurion.

I saw the diagram but personally I have no idea about Electricity thing.

It does show some diagram of steering wheel buttons too so someone please explain what we have to do.

[Kmg]

From what I read in Camry service manual in the sticky post Navigation system page NS-162, the steering pad switch assembly is slightly different with Aurion's. Since the aftermarket head unit is designed for Camry, it is not surprising that display button won't work. Can anyone upload a copy of Aurion service manual to see the wiring setting of Aurion's steering pad switch assembly?

I think you better have a look at the Electric wiring diagram.

The manual is on this forum one of the pinned at the top.

It gives you all the details of eclectric wiring diagram of GSV40 Series and ACV40 Series.

The GSV40 is aurion.

I saw the diagram but personally I have no idea about Electricity thing.

It does show some diagram of steering wheel buttons too so someone please explain what we have to do.

I am talking about that sticky post too. It is US V6 Camry service manual, GSV40 is not Aurion but Camry V6, they are 99% the same but not identical, at least DISP button is not. If we have the real Aurion manual, we can compare and find out which one of the 4 wires from steering pad switch assembly is DISPLAY button and jump it to the correct spot in Head unit.

Of course, some one who is familiar with car electronic can study the US Camry service manual, find out which spot is DISPLAY button and test all the 4 wires by trial and error.

[DJKOR]

from my memory, no one who is using an aftermarket HU(other than the one bought from ebay) can still use their display button... tracking the display button's wire, it leads back to the HU.. weird..

Nope I got the display to work, you can bypass the HU, the HU doesnt control the display, so look for a orphan wiring that is neither power, antenna or speakers and bingo.

Can you please explain?

I was thinking to connect that cable with other cable such as ground? cos it looks like nothing with HU.

But I am just worrying about if I connect it with wrong one and the display is f**ked.

Which cable (which colour?) did you hook it up to?

From my observation, connecting any one of those wires to ground is going to serious break something. That part of the circuit appears to be isolated from ground and judging from the voltage readings obtained, it appears to be part of a digital circuit.

That's why I am quite curious to find out if there really is a simple way to fix it.

[DJKOR]

From what I read in Camry service manual in the sticky post Navigation system page NS-162, the steering pad switch assembly is slightly different with Aurion's. Since the aftermarket head unit is designed for Camry, it is not surprising that display button won't work. Can anyone upload a copy of Aurion service manual to see the wiring setting of Aurion's steering pad switch assembly?

I think you better have a look at the Electric wiring diagram.

The manual is on this forum one of the pinned at the top.

It gives you all the details of eclectric wiring diagram of GSV40 Series and ACV40 Series.

The GSV40 is aurion.

I saw the diagram but personally I have no idea about Electricity thing.

It does show some diagram of steering wheel buttons too so someone please explain what we have to do.

I am talking about that sticky post too. It is US V6 Camry service manual, GSV40 is not Aurion but Camry V6, they are 99% the same but not identical, at least DISP button is not. If we have the real Aurion manual, we can compare and find out which one of the 4 wires from steering pad switch assembly is DISPLAY button and jump it to the correct spot in Head unit.

Of course, some one who is familiar with car electronic can study the US Camry service manual, find out which spot is DISPLAY button and test all the 4 wires by trial and error.

I don't think anyone out there has leaked te Aurion service manual. We need someone nice enough from Toyota to do that for us first.

As for the DISP button thing; I've looked into it, and from my perspective, it is definitely a digital circuit. I have tested both from the point of the steering wheel controls and from the end of the harness at the stereo end. I would help to find a solution if I could, but I don't want to risk destroying something that works, without first learning about the backbones of this system.

My testing wasn't extensive, but my readings were from the stereo end:

Purple: 0V when ignition is off - 10.97V when ignition is on.

Pink: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

Orange: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

Yellow: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

As you can see, the pink, orange, and yellow all behave the same when the DISP button is pressed. One interesting note is that pressing any of the audio buttons on the steering wheel gave no readings on those wires when pressed. These conditions can easily change when they are in circuit.

[JIN]

From what I read in Camry service manual in the sticky post Navigation system page NS-162, the steering pad switch assembly is slightly different with Aurion's. Since the aftermarket head unit is designed for Camry, it is not surprising that display button won't work. Can anyone upload a copy of Aurion service manual to see the wiring setting of Aurion's steering pad switch assembly?

I think you better have a look at the Electric wiring diagram.

The manual is on this forum one of the pinned at the top.

It gives you all the details of eclectric wiring diagram of GSV40 Series and ACV40 Series.

The GSV40 is aurion.

I saw the diagram but personally I have no idea about Electricity thing.

It does show some diagram of steering wheel buttons too so someone please explain what we have to do.

I am talking about that sticky post too. It is US V6 Camry service manual, GSV40 is not Aurion but Camry V6, they are 99% the same but not identical, at least DISP button is not. If we have the real Aurion manual, we can compare and find out which one of the 4 wires from steering pad switch assembly is DISPLAY button and jump it to the correct spot in Head unit.

Of course, some one who is familiar with car electronic can study the US Camry service manual, find out which spot is DISPLAY button and test all the 4 wires by trial and error.

I don't think anyone out there has leaked te Aurion service manual. We need someone nice enough from Toyota to do that for us first.

As for the DISP button thing; I've looked into it, and from my perspective, it is definitely a digital circuit. I have tested both from the point of the steering wheel controls and from the end of the harness at the stereo end. I would help to find a solution if I could, but I don't want to risk destroying something that works, without first learning about the backbones of this system.

My testing wasn't extensive, but my readings were from the stereo end:

Purple: 0V when ignition is off - 10.97V when ignition is on.

Pink: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

Orange: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

Yellow: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

As you can see, the pink, orange, and yellow all behave the same when the DISP button is pressed. One interesting note is that pressing any of the audio buttons on the steering wheel gave no readings on those wires when pressed. These conditions can easily change when they are in circuit.

If you see the diagrm from sticky post, the purple(violet in the diagrm) is the only one connected directly to the speedo circuit and it seems like it's independent from the other 3 cables(orange, pink and yellow). I can't be sure I got the right idea or not, but from the diagram, I can't find the display button although all other buttons, such as seek and mode, are named in steering pad sw section in the diagram.

So in that case, I guess the violet one looks like the display button circuit.

If I assume the violet is the display button, can I just hook it up with ignition cable?

What would be the worst case of connecting wrong cable?

Can anyone please explain this diagram and give us any hints?

Edited August 2, 2008 by JIN

[DJKOR]

Hey JIN. If I were you, I wouldn't go messing with that violet cable. That is actually connected to the Combination Meter and speed sensor ECU. Worst case scenario if you mess that up is that you will fry something in the Combination Meter which will you will be regretting if you did.

This whole display/steering wheel control thing isn't just a matter of joining wires. That's it. If you want to go understanding how it all works, you will need to get a circuit diagram for the stock stereo (or any compatible aftermarket stereo) and analyze how how the harness connects to it.

[JIN]

Hey JIN. If I were you, I wouldn't go messing with that violet cable. That is actually connected to the Combination Meter and speed sensor ECU. Worst case scenario if you mess that up is that you will fry something in the Combination Meter which will you will be regretting if you did.

This whole display/steering wheel control thing isn't just a matter of joining wires. That's it. If you want to go understanding how it all works, you will need to get a circuit diagram for the stock stereo (or any compatible aftermarket stereo) and analyze how how the harness connects to it.

Yeah, I wouldn't give it a try before everything is clear. I think we really need an expert to explain and analyze on this matter.

I really am wondering how acoustik has played with all those calbes and made it working.

[DJKOR]

Hey JIN. If I were you, I wouldn't go messing with that violet cable. That is actually connected to the Combination Meter and speed sensor ECU. Worst case scenario if you mess that up is that you will fry something in the Combination Meter which will you will be regretting if you did.

This whole display/steering wheel control thing isn't just a matter of joining wires. That's it. If you want to go understanding how it all works, you will need to get a circuit diagram for the stock stereo (or any compatible aftermarket stereo) and analyze how how the harness connects to it.

Yeah, I wouldn't give it a try before everything is clear. I think we really need an expert to explain and analyze on this matter.

I really am wondering how acoustik has played with all those calbes and made it working.

I'm curious as well. The best solution I have found is to dissect the old factory stereo and remove the main circuit board. Then to plug the remote harness into that and 'hide' the circuit board somewhere. It is quite odd that they have chosen to have the control circuitry for the steering wheel buttons in the stereo; which runs independently since the stereo doesn't need to have power applied to it for that end of the circuit to work. In a way, I guess that means Toyota can get it their way by preventing aftermarket modifications.

[JIN]

Hey JIN. If I were you, I wouldn't go messing with that violet cable. That is actually connected to the Combination Meter and speed sensor ECU. Worst case scenario if you mess that up is that you will fry something in the Combination Meter which will you will be regretting if you did.

This whole display/steering wheel control thing isn't just a matter of joining wires. That's it. If you want to go understanding how it all works, you will need to get a circuit diagram for the stock stereo (or any compatible aftermarket stereo) and analyze how how the harness connects to it.

Yeah, I wouldn't give it a try before everything is clear. I think we really need an expert to explain and analyze on this matter.

I really am wondering how acoustik has played with all those calbes and made it working.

I'm curious as well. The best solution I have found is to dissect the old factory stereo and remove the main circuit board. Then to plug the remote harness into that and 'hide' the circuit board somewhere. It is quite odd that they have chosen to have the control circuitry for the steering wheel buttons in the stereo; which runs independently since the stereo doesn't need to have power applied to it for that end of the circuit to work. In a way, I guess that means Toyota can get it their way by preventing aftermarket modifications.

Oh. you mean I can just remove the board from HU and hide it after connecting the harness into the board?

Does display button still work in that way without any power supply to it??

[dannywss]

Hey JIN. If I were you, I wouldn't go messing with that violet cable. That is actually connected to the Combination Meter and speed sensor ECU. Worst case scenario if you mess that up is that you will fry something in the Combination Meter which will you will be regretting if you did.

This whole display/steering wheel control thing isn't just a matter of joining wires. That's it. If you want to go understanding how it all works, you will need to get a circuit diagram for the stock stereo (or any compatible aftermarket stereo) and analyze how how the harness connects to it.

Yeah, I wouldn't give it a try before everything is clear. I think we really need an expert to explain and analyze on this matter.

I really am wondering how acoustik has played with all those calbes and made it working.

I'm curious as well. The best solution I have found is to dissect the old factory stereo and remove the main circuit board. Then to plug the remote harness into that and 'hide' the circuit board somewhere....

actually this is wat my mate is helping out with now.. hope it works, and i heard it should be possible..

sad that i hvnt seen him explaining how he actually made it work.. :(

[DJKOR]

Oh. you mean I can just remove the board from HU and hide it after connecting the harness into the board?

Does display button still work in that way without any power supply to it??

Sure does. The control circuitry in the head unit for that part gets its power from the harness in question. It's quite a messy way to do it, but unless someone how is good at reverse engineering can figure it out from the circuit board alone, then that's one way of doing it. Heard about it from the guys over at the US forums, and realised that when I had the power to my head unit disconnected, yet the DISP button worked perfectly fine. It only stopped working when the harness for the steering controls were completely disconnected from the head unit.

[Kmg]

From what I read in Camry service manual in the sticky post Navigation system page NS-162, the steering pad switch assembly is slightly different with Aurion's. Since the aftermarket head unit is designed for Camry, it is not surprising that display button won't work. Can anyone upload a copy of Aurion service manual to see the wiring setting of Aurion's steering pad switch assembly?

I think you better have a look at the Electric wiring diagram.

The manual is on this forum one of the pinned at the top.

It gives you all the details of eclectric wiring diagram of GSV40 Series and ACV40 Series.

The GSV40 is aurion.

I saw the diagram but personally I have no idea about Electricity thing.

It does show some diagram of steering wheel buttons too so someone please explain what we have to do.

I am talking about that sticky post too. It is US V6 Camry service manual, GSV40 is not Aurion but Camry V6, they are 99% the same but not identical, at least DISP button is not. If we have the real Aurion manual, we can compare and find out which one of the 4 wires from steering pad switch assembly is DISPLAY button and jump it to the correct spot in Head unit.

Of course, some one who is familiar with car electronic can study the US Camry service manual, find out which spot is DISPLAY button and test all the 4 wires by trial and error.

I don't think anyone out there has leaked te Aurion service manual. We need someone nice enough from Toyota to do that for us first.

As for the DISP button thing; I've looked into it, and from my perspective, it is definitely a digital circuit. I have tested both from the point of the steering wheel controls and from the end of the harness at the stereo end. I would help to find a solution if I could, but I don't want to risk destroying something that works, without first learning about the backbones of this system.

My testing wasn't extensive, but my readings were from the stereo end:

Purple: 0V when ignition is off - 10.97V when ignition is on.

Pink: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

Orange: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

Yellow: 0V when ignition is on or off - 4.69V when DISP button is pressed - 10.97V when parker lights are on (will remain at 10.97V even if DISP is pressed)

As you can see, the pink, orange, and yellow all behave the same when the DISP button is pressed. One interesting note is that pressing any of the audio buttons on the steering wheel gave no readings on those wires when pressed. These conditions can easily change when they are in circuit.

If you go to sticky post, or here:

http://www.camrystuff.com/manuals/Gen6/2GR...udio_Visual.pdf

Page AV-92, you can see the 3 spoke type is similar to our Aurion steering pad switch. Assuming DISP is the the one unlablled gate at the right of off-hook gate in RH side circuit , it is using both EAU and AU2 to signal the HU. Now since DISP is part of a circuit, it is normal that pink, orange and yellow lines will have readings when you tested them. But by looking at the circuit board from your photo, DISP has another contact point, which is separated from EAU and AU2, now I am really confused.

Edited August 6, 2008 by Kmg

[DJKOR]

...But by looking at the circuit board from your photo, DISP has another contact point, which is separated from EAU and AU2, now I am really confused.

Mate; I'm confused as well. To seriously get to the bottom of it, one would need to trace all the wires to see where they go to, including pulling out the speedo. That would really help to get a better understanding. All I know is that by unplugging the cable from the head unit, you loose display functionality, so this is more than just following cables. Sorry, but I'm not that good at reverse engineering digital circuits.

[David the Viking]

Looking at the electrical diagrams and from my understanding the DISP button has nothing to do with the Radio/Audio system but is actually interconnected with the A/C system.

DJKOR my question is when you had the radio plugs disconnected and lost the DISP button function did you also have the A/C unit plugs disconnected? If so this would explain why it didnt work.

Page 368 of the 07EWD.pdf shows the DISP button and page 371 & 389 show the A/C system connection.

http://www.camrystuff.com/manuals/Gen6/Mis...neous/07EWD.pdf

Edited August 6, 2008 by SupaTouring

[DJKOR]

Looking at the electrical diagrams and from my understanding the DISP button has nothing to do with the Radio/Audio system but is actually interconnected with the A/C system.

DJKOR my question is when you had the radio plugs disconnected and lost the DISP button function did you also have the A/C unit plugs disconnected? If so this would explain why it didnt work.

Page 368 of the 07EWD.pdf shows the DISP button and page 371 & 389 show the A/C system connection.

http://www.camrystuff.com/manuals/Gen6/Mis...neous/07EWD.pdf

You know what? To pull the head unit forward, the A/C controls were one of the first connectors to be disconnected. Being the curious type, I will go downstairs and checked it out. Here are some further observations. These are with my new aftermarket Auspack head unit.

Disconnecting everything from the head unit and only leaving the steering wheel harness connected, the DISP button works in switching the in-dash display between page; and this is with the aftermarket unit. Disconnecting the A/C controls have no effect on whether or not the DISP button works.

Now for the aftermarket unit, it makes use of the following wiring harness:

To connect to the steering wheel harness:

Now only the PINK, ORANGE, and YELLOW wires are used; which is to be expected since the PURPLE one is for the speedo sense.

On the aftermarket wiring harness, the ORANGE and YELLOW wires are joined together by means of a 2k ohm resistor (measuring 1.976k ohms). So therefore, there are only two wires connecting to the head unit essentially. I have used these two wires to get resistance measurements, though I doubt this would be of any use. This is the reading looking at the steering wheel buttons through the harness without it connected to anything. All figures are average:

No button pressed: 40.77 ohms

Volume down: 2.9k ohms

Volume up: 1.0k ohms

Seek down: 330 ohms

Seek up: 1.2 ohms

Mode: 1.93k ohms

DISP: [wouldn't stay steady on one value] approximately 0.2 ohms

Another interesting thing to note is that without the steering wheel harness connected into anything, the buttons will not light up when the parkers are turned on.