Honda / Acura Music Link (Technical)
This page contains general information about the cables and PCB used in the Honda / Acura Music Link. This information was discovered during my experimentation with the Honda Music Link.
No guarantees are made about the accuracy of this information, although I believe it to be correct.
- 9600, 8N1
- Communication via Apple Accessory Protocol in Mode 0x04 / AiR.
- An example conversation between the Honda Music Link and a 5G 30GB iPod (Video) can be seen here. Decoding of many of the packets has been done by hand.
These pinouts were established via direct testing with the named cables, a disassembled Honda Music Link interface box, and a document detailing pinouts of connectors in 2006 Honda Civic vehicles.
Cable from Head Unit (HU) to Interface Box (IB)
- SAT R(+), SAT L(+), SAT R(-), and SAT L(-) are the connections which pass audio.
- SAT ECU BUS (+) and SAT ECU BUS (-) appear to handle data for signaling to the iPod / Interface Box.
|HU Pin||HU Description||IB Pin|
|2||SAT SYS ACC||6|
|5||SAT R (+)||5|
|6||SAT L (+)||3|
|9||SAT ECU BUS (+)||8|
|10||SAT ECU BUS (–)||7|
|13||SAT R (–)||4|
|14||SAT L (–)||2|
Cable from Interface Box (IB) to iPod Dock Connector (iPod)
- iPod Pin Numbering is 1 through 30, with Pin 1 being on the left when the iPod dock connector is held connector up with the dock connector logo facing the viewer. The keyed face of the connector and the wires inside of the connector will be towards the viewer when held in this position.
- Pin 21 on the iPod dock connector is tied to pins 29+30 in the connector with a 500K resistor. This is consistent with the iPod Linux Dock Connector information. This resistor appears to be located in the connector shell.
- Pin 18 on the iPod dock connector, which sends 3.3v from the iPod, is used by the Honda Music Link to detect the presence of an iPod. Connecting this line takes the head unit out of EJECT mode and the Honda Music Link then begins first data transmissions, alternately sending the command to switch the iPod into Mode 4 (FF 55 03 00 01 04 F8) and querying the iPod for its type and size (FF 55 03 04 00 12 E7).
|IB Pin||iPod Description||iPod Pin|
|1||FireWire +12 VDC||19+20|
|3||Line Out (L)||4|
|4||Line Out (GND)||2|
|5||Line Out (R)||3|
|6||+3.3 VDC Power||18|
DIN Connectors on Interface Board PCB
As viewed from the bottom (non-component-bearing) side of the PCB, with the connector-bearing edge of the PCB upwards:
|SAT R (+)||SAT L (-)||No Desc. (Pin 7 on Con. E)||SAT L (+)|
|SAT ECU BUS (+)||SAT ECU BUS (-)||SAT R (-)||SAT SYS ACC|
|Line Out (R)||FireWire Ground||FireWire +12 VDC||Line Out (L)|
|Serial TX||Serial RX||Line Out (GND)||+3.3 VDC|
JP1 Header to PIC16F876
- Appears to be pin compatible with the Microchip PICkit2 Development Programmer, except the PICkit2 has a 1x6 pin configuration whereas the IB has a 2x3.
As viewed from the top (component-bearing) side of the PCB, with the Mini-DIN connector-bearing edge of the PCB to the left:
JP1 to PIC16F876A Viewed from Above
Click component name for data sheet or other relevant information.
|J1||Socket, Mini-DIN, 8-Pin|
|J2||Socket, Mini-DIN, 8-Pin|
|JP1||Header, .100" Spacing, .250" Long Pins|
|U1||National Semiconductor LP2950 (5V)|
|U5||(Missing from board?)|
|U6||National Semiconductor LP2950 (3.3V)|
|U7||(Missing from board?)|
|U8||UTC MC4558 (SOP-8)|
|Y1||3.686 MHz Crystal|
|Y3||6.290 MHz Crystal|