Getting the steering wheel buttons to work with the Seicane radio

[Fubar]

I got this Seicane Android radio for my 2002 KJ Liberty because it is the same shape/size as the factory unit and fits on the existing bezel with no need for modifications.

I won't bother describing the installation, because it is quite straightforward. Adapters for factory harness and antenna are included so it is pretty much plug-and-play.

What is not so straightforward is how to get the steering wheel controls to work with this unit.

Good news is that you won't need a special CANbus decoder box.

However a small modification is required because as it turns out, the steering wheel button voltage is slightly higher than what the Seicane can sense.

First step is to remove the steering column plastic cover. It is held by two torx T20 screws

Once you get this off, this is what you'll see:

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A yellow and a white connector.

The wire that corresponds to the steering wheel buttons is the middle one on the white connector (red with blue stripe)

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Normally, we would splice the wire marked KEY 1 or KEY 2 from the Seicane harness to this red with blue stripe wire and be done with it.

I did just that, and while it seemed to work, I couldn't map the keys that are normally for volume up/down on the SWC app.

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I noticed that the voltage generated on the red/blue stripe wire when those two buttons are pressed is the highest relative to other buttons.

Here are the voltages that correspond to each button:

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4.99 Volts when no button is pressed, 3.49 when Volume Up is pressed and 4.25 for Volume Down

Apparently the Seicane works on 3.3 Volts internally so it can't recognize anything above that.

So I used a potentiometer between the steering wheel wire and Seicane to drop the voltage. I set it at the midpoint, which means all voltages would be halved.

And it worked! All buttons could be mapped on the SWC application.

Here's my test apparatus, the potentiometer shown by the red arrow

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You must be registered for see images attach

I didn't have the time to make permanent connections, so I removed all extra wiring and put the radio back in.

If I find some time tomorrow, I will make a simple resistive divider (more reliable than a potentiometer) and splice it on the steering wheel wire. I'll post detailed photos and maybe a video.

 

[Fubar]

This is what the resistive voltage divider should look like

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Two resistors of equal value will divide voltage by 2. The value isn't super important, anything from 10K to 100K should work.

 

[Fubar]

Ok, first let's make the ground connection. One way would be to splice it on the main harness, but I chose a more creative way:

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I am taking the black wire from an old computer PSU.

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My crimping tool

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Screwed it on the side of the unit!

 

[Fubar]

Now let's splice a wire on the steering wheel red/blue stripe wire.

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This is going to be the extra length of wire to be spliced

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Harness wire cut and ends stripped

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One end crimped

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Both ends crimped. I then wrapped it with some electrical tape to keep everything in place

 

[Fubar]

Now to make the voltage divider and final connections. These are the resistors I'm using, plain old 1/4W, 12Kohm ones.

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Soldering one resistor on the green wire

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And this is what the final result should look like

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The other resistor soldered on the ground wire and the KEY 1 wire soldered on the mid point between the two resistors.

Just remember to slide some heatshrink before making the final solder!

 

[Fubar]

And everything works fine. All 6 buttons mapped out:

You must be registered for see images attach

And a video:

https://streamable.com/ems75

Hope you found this guide helpful.

 

[Leinenkugel]

I got this Seicane Android radio for my 2002 KJ Liberty because it is the same shape/size as the factory unit and fits on the existing bezel with no need for modifications.

I won't bother describing the installation, because it is quite straightforward. Adapters for factory harness and antenna are included so it is pretty much plug-and-play.

What is not so straightforward is how to get the steering wheel controls to work with this unit.

Good news is that you won't need a special CANbus decoder box.

However a small modification is required because as it turns out, the steering wheel button voltage is slightly higher than what the Seicane can sense.

First step is to remove the steering column plastic cover. It is held by two torx T20 screws

Once you get this off, this is what you'll see:

You must be registered for see images attach

A yellow and a white connector.

The wire that corresponds to the steering wheel buttons is the middle one on the white connector (red with blue stripe)

You must be registered for see images attach

Normally, we would splice the wire marked KEY 1 or KEY 2 from the Seicane harness to this red with blue stripe wire and be done with it.

I did just that, and while it seemed to work, I couldn't map the keys that are normally for volume up/down on the SWC app.

You must be registered for see images attach

I noticed that the voltage generated on the red/blue stripe wire when those two buttons are pressed is the highest relative to other buttons.

Here are the voltages that correspond to each button:

You must be registered for see images attach

4.99 Volts when no button is pressed, 3.49 when Volume Up is pressed and 4.25 for Volume Down

Apparently the Seicane works on 3.3 Volts internally so it can't recognize anything above that.

So I used a potentiometer between the steering wheel wire and Seicane to drop the voltage. I set it at the midpoint, which means all voltages would be halved.

And it worked! All buttons could be mapped on the SWC application.

Here's my test apparatus, the potentiometer shown by the red arrow

You must be registered for see images attach

You must be registered for see images attach

I didn't have the time to make permanent connections, so I removed all extra wiring and put the radio back in.

If I find some time tomorrow, I will make a simple resistive divider (more reliable than a potentiometer) and splice it on the steering wheel wire. I'll post detailed photos and maybe a video.

Hello,

Hoping you can shed some light on how you determined that red/blue wire was the steering wheel control wire? I have a 2005 KJ and that white plug has a sixth wire on my harness, and none of them are red/blue. I'm assuming it is still going to be one of those wires that controls the SWC buttons but I'm not sure how to figure out which one it is. Great write up, thanks!!

 

[DadOSix]

And everything works fine. All 6 buttons mapped out:

You must be registered for see images attach

And a video:

https://streamable.com/ems75

Hope you found this guide helpful.

Dang fine work!

thanks for posting it up!

 

[Leinenkugel]

Hello,

Hoping you can shed some light on how you determined that red/blue wire was the steering wheel control wire? I have a 2005 KJ and that white plug has a sixth wire on my harness, and none of them are red/blue. I'm assuming it is still going to be one of those wires that controls the SWC buttons but I'm not sure how to figure out which one it is. Great write up, thanks!!

I think I figured it out! Used a multimeter and probed each wire in the white plug to find which wires had voltage, then pushed the steering wheel buttons to find which wire would fluctuate when the button was pressed on the steering wheel and boom goes the dynamite. On my 2005 KJ CRD Limited the grey wire with orange stripe is the SWC wire!