Project: Factory Bluetooth on EX wo/navi on non-navi aftermarket head unit

[wizkid057]

So, I've been hunting these forums, google, and other sources trying to determine a few things. These forums by far have the most data!

How exactly does the "Hands Free Link" setup work from a technical standpoint? I read that it is a separate module.

It obviously works with the EX factory head unit, but, what type of interface is it? Where are the audio feeds (factory microphone, audio out to radio) and the triggers for it all?

I read that the factory steering wheel buttons for calling work with some Pioneer brand head units with Bluetooth, but not with the factory microphone, so, assuming it is not using the factory Bluetooth unit and you lose the in-dash displays and voice commands from it.

Ideally, I want to be able to install a head unit setup that does not on it's own support Bluetooth and retain the factory Hands Free Link setup. I have a decent amount of technical knowledge in hardware, embedded systems, software design, etc. Perhaps I need to make some type of interface to work with it.

I really don't have enough information because what I've been able to find online seems pretty limited. I also have not physically dismantled anything related to it on my own vehicle yet, so, that may be next.

So, in summary, I'm looking for any details on:

• Hands Free Link "module" and it's connections
• Steering wheel buttons and their wiring/interface (both radio controls and Bluetooth)
• Any related helpful information (harnesses/module pics maybe?, pinout data?)

Thanks in advance!

[wizkid057]

I seem to be replying to myself... however, I think I have the needed information!

After much digging through Honda technical documents I *believe* I have the answers to my questions.

In short, yes, it should definitely be possible to use the Bluetooth HandsFreeLink module from a CR-Z EX non-navi with an aftermarket head unit with some tweaking and additional hardware. The HFL module on the navi units seems to require different signaling, as the head unit actually communicates with the modules both ways.

I'm not 100% sure on this, as I have not tried it yet, but, it seems that even with the radio disconnected the Bluetooth module should still respond to button presses. However, I'm not 100% sure how this wiring works for the buttons. The pin A11 from the factory audio unit may need to be grounded. Not sure... some testing needed.

So, supposing it does work, the audio output from the HFL module comes from the 12-pin connector on the factory unit.

Pin 1 should be high if the bluetooth icon should be displayed. Pin 8 should be high if the bluetooth system is playing audio. Pins 9 and 10 are pre-amp audio positive and negative respectively.

This is all derived from the technical data I've been able to locate through techinfo.honda.com. My interpretation may not be accurate. I plan on actually testing all of this within the next couple of weeks.

-wk

[Gumbercules]

awesome findings, i would love to know how it works for you

[hoisumguo]

Thx for posting answers (even to your own question) back to the forum. I'm sure it will be very helpful to others.

-Hoi