Pinouts >  Aftermarket automotive Head units and Car Stereo

unknown connector
various abbreviations with descriptions

Meaning of Head Unit pinout signals

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 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

anti-theft alarm system

SDARS Satellite Digital Audio Radio Service
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)


According to 2 reports in our database (2 positive and 0 negative) the Head units contacts labels and meaning of pinout should be correct.

Is this pinout
Head units contacts labels and meaning of visual pinout:click to enlarge
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