Meaning of Head Unit pinout signals
| Pin Notation |
Pin function |
|---|---|
Power pins |
|
| B+, BAT, Bup+, Ub+, B-U, MEM +12, KL.30 | Battery+ (12V direct from Battery). |
| GND, GROUND | Chassis Ground |
| A+, ACC, S-K, S-kont, SWA, KL.15 | Ignition powered. +12 V with the ignition key is in the ACC or ON position. |
| ILL, LAMP, Lume, iLLUM, lightbulb image | Light-on signal or backlight adjustment. +12V supplied to light-on pin of head unit when tail lights ar turned on. May be used for backlight adjustment in some models. |
| ANT+, P.ANT, ANT | Power for Electric Antenna. Output +12 V (maximum 150 - 300mA) |
| __/ +--- | Switched power out |
Audio pins |
|
| FR+ or RF+ | Front right speaker out |
| FL+ or LF+ | Front left speaker out |
| RR+ | Rear right speaker out |
| LR+ or RL+ | Rear left speaker out |
| FR- or RF-, FL- or LF-, RR-, LR- or RL-, SGND | The corresponding speaker ground |
| LINE OUT, LINE-OUT LF, LINE-OUT RF, LIN, LIN-R, LIN-L | Audio line out |
| LINE IN | Audio line in |
| FR PRE, FL PRE, RR PRE, LR PRE | Audio out for preamlifier |
Misc. pins |
|
| MUTE, Mut, mu, TEL, TEL MUTE, strikeout speaker | This pin is used to silence the audio, earthed by some other external components that is connected to the radio. |
| GALA,GAL, GA, SCV, SDV | This pin is used in some radio equipment to automatically boost up the volume. It needs the output from the speed sensor. |
| Amp, ATX+, ATX- | Amplifier control |
| SW+B | Switch to battery |
| DATA, CLOCK | Head unit communication |
| CAN-L, CAN-H | CAN on board diagnostic bus |
| K-BUS | K-line on board diagnostic bus |
| J1850 | J1850 Car On Board Diagnostic |
| SW +B, SWD +B | Switched battery power (i.e. for preamplifier) |
| SDA, SCL, MRQ | Head unit communication (information display and so on) |
| CD-IN L+, CD-IN L-, CD-IN R+, CD-IN R-, CL, CH, IH, CDL, CDR | CD-changer audio |
| TXM+, TXM-, TXS+, TXS- | Changer to Head unit (Master) and Head Unit to changer (Slave) |
| RC-IN, RC-GND, /- RC +12V, FB-IN, R-CON | Remote control |
| DWA, DWA-GND, Alarm-GND |
anti-theft alarm system |
| SDARS | Satellite Digital Audio Radio Service |
| PWM | Pulse Width Modulation. Usually control the brightness of LEDs, sometimes speed of misc motors. |
| HFL | HandsFree related |
| DAB | Digital Audio Broadcasting |
| SWC, SW | Steering wheel control buttons |
| ACP | Audio Control Protocol |
| SCTY | Security signal from Multiplex integrated control unit (Honda MICU) |
correct
incorrect