2020 CTR Head unit - Free connector on the back side - What is it for ?

[JDM Power]

Hi, guys !
After the removing of the head unit, once with the reinstallation, I observed that one of the thirteen connectors on the back side are free.
Because when I removed the head unit, I didn’t count how many connectors are used, I was affraid not to forget one of them and I investigate more, but that’s all, only twelve are assigned to cables.
I wonder what the free connector is for ? I presume that the free 12 pin connector is for an amp, but I am not sure.
The free connector is on the middle row, below the central biggest one.
Thank you very much.

(In the left side of the central white connector).
If somebody can show a diagram with the destination of the each of them, will be much appreciated.

 

[Tekprime]

Do you have interior floor well lighting? I know that harness connects somewhere to the headunit

 

[JDM Power]

Yes, I have (SKU 08E10-TEA-600A), but it is connected to power to the fuse box, like the illuminated door sill trims too, not to the head unit.
Here is my fuse box, the power footwell connector is the 6-pin one wich is connected behind the 2 Amp fuse for the step illuminated steps, into the 6-pin connector of the illuminated steps harness.
Anyway, the interior illumination kits have 6-pin connectors, not 12-pin connectors, like the free head unit one, I am interested in.

 

[JDM Power]

After a detailed research, I succeded to find this :

On the upper row, from left to the right :

1. Roof antenna connector L (2 Pin)- Communication signal for tuner unit - SPDIF 1

2. Audio unit connector C (32 Pin)- Power and video signal for rearview camera, inputs sound signal from HFL microphone

3. Audio unit connector B (24 Pin)- Outputs signal for speakers



On the middle row, from left to the right :

1. Audio remote HFL switch (12 Pin) connector for inputs and outputs - Outputs illumination signal for cruise control combination switch, ground for audio remote - HFL switch (G502), communication signal for gauge control module.
This is the connector that remained unallocated, and I am interested in.

2. Audio unit connector M (4 Pin)-(with stereo amplifier)- Communication signal for stereo amplifier - SPDIF 2

3. Audio unit connector E (16 Pin) - Power source for tuner unit, communication signal for tuner unit and stereo amplifier, outputs signal for center display switching on/off.
4. ???


On the lower row, from left to the right :

1. Audio unit connector K (2 Pin)- (Female terminals)- Inputs GPS signal from GPS antenna
2. Audio unit connector J (3 Pin)- (Female terminals)- Communication signal for gauge control module
3. Audio unit connector H (3 Pin)- (Female terminals)-Communication signal for center display unit
4. ???
5. Audio unit connector G (5 Pin)- (Female terminals)-Outputs power source for USB port B
6. Audio unit connector F (5 Pin)- (Female terminals)-Outputs power source for USB port A

Now, I wonder how it is possible the 12 Pin connector on the middle row to be free, since my car have all the options, including cruise control and audio remote HFL switch on the steering wheel ?
My biggest concern now, with the fact that I've already reinstalled the head unit, is that I haven't forgotten to plug in any cables, although I did look carefully inside the console.
I don't think that 12-pin connector it would have had a cable that dropped into the bottom of the console, because that would have meant it was not clamped to a fairly long length, which I don't think the factory would have done.
Any help will be much appreciated. Thank you.

 

[Andruboine]

Could be that they reuse that HeadUnit for other models that need that plug in.

 

[arekp]

@JDM Power, did you ever find out what "Audio remote HFL switch (12 Pin) connector" is for?

 

[JDM Power]

@JDM Power, did you ever find out what "Audio remote HFL switch (12 Pin) connector" is for?

Nope, sorry.

 

[BrandonSmith]

Whatever you do, do not plug a different connector in there. Some people have fried their head units by plugging the wrong thing in to that open connector.

 

[arpypat]

Per Honda, this is used as a service port for markets outside of North America. They state that their 12-pin plug for the illumination kit will fit the socket, but it's not intended for that.

https://www.civicx.com/forum/threads/2016-17-ex-factory-radio-wiring-diagram-needed.9808/post-804790

 

[BrandonSmith]

Whatever you do, do not plug a different connector in there. Some people have fried their head units by plugging the wrong thing in to that open connector.

Per Honda, this is used as a service port for markets outside of North America. They state that their 12-pin plug for the illumination kit will fit the socket, but it's not intended for that.

https://www.civicx.com/forum/threads/2016-17-ex-factory-radio-wiring-diagram-needed.9808/post-804790

Yeah, that’s what I was talking about…

Although the 12-pin connector for the panel and the kit's ambient light harness fit right into that empty cavity, plugging them in will damage the dimming circuit in the gauge control module, causing a loss of the shift indicators and other switch backlighting.