Mercedes-Benz / Smart OEM Head Unit Pinouts

Factory connector layouts and pin assignments for Mercedes-Benz and Smart radios, navigation units and TV tuners. Match the model, part number and connector orientation before using a pin table.

Mercedes-Benz

Mercedes-Benz Audio 10

Mercedes Benz Audio 10 by Becker (BE3100) p/n A 210 820 09 86; Mercedes Benz Audio 10 by Becker (BE3200) p/n A 208 820 03 86; Mercedes Benz Audio 30 by Becker (BE3307) Mercedes Benz Audio 30 APS (BE4705); Mercedes Benz CD (MF2297) by ALPINE (Japan);Mercedes Benz Truckline CC25 (BE6046)

Connector overview

Power and control

Pin	Signal
1	Speed pulse
2	—
3	Telephone mute
4	Battery positive (30)
5	Antenna enable
6	Illumination
7	Switched supply (15)
8	Ground (31)

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

CD changer

Pin	Signal
4	CD changer control
5	CD changer battery supply
6	CD changer ground

Mercedes-Benz Audio 10 CD (1999-2002) Head Unit

Alpine MF2199

Connector overview

Power and control

Pin	Signal
1	Speed pulse
2	Diagnostics / configuration
3	Telephone mute
4	Battery positive (30)
5	Antenna enable
6	Illumination
7	Switched supply (15)
8	Ground (31)

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

CAN and CD changer

Pin	Signal
1	CAN high
2	CAN low
4	D2B wake-up
5	CD changer battery supply
6	CD changer ground

Mercedes-Benz Audio 20 Head Unit (2004-2010)

Connector overview

Master connector reference · 40-pin Quadlock radio socket

Main Quadlock

Pin	Signal
1	Rear right (+)
2	Front right (+)
3	Front left (+)
4	Rear left (+)
5	Rear right (−)
6	Front right (−)
7	Front left (−)
8	Rear left (−)
9	Body CAN low
10	Telephone mute
11	Body CAN high
12	Ground (31)
13	Antenna enable
14	—
15	Battery positive (30)
16	Wake-up

Auxiliary audio

Pin	Signal
4	AUX shield
5	AUX supply
6	AUX left
11	AUX ground
12	AUX right

Telephone interface · Japan

Pin	Signal
1	Voice audio (+)
2	Voice audio (−)
3	Audio ground
4	Microphone mute
5	Telephone interface wake-up
6	UART RX shield
7	UART RX (+)
8	UART RX (−)
9	UART TX shield
10	UART TX (+)
11	UART TX (−)

MOST fibre

Pin	Signal
1	Optical receive
2	Optical transmit

Mercedes-Benz Audio 20 W211 (2006-2009), S211 (2002-2009) MF2310 Head Unit

p/n A 211 820 97 89, A 211 870 11 89

Connector overview

Master connector reference · 40-pin Quadlock radio socket

Main Quadlock

Pin	Signal
1	Front left (+)
2	Front left (−)
3	Rear left (+)
4	Rear left (−)
5	Front right (+)
6	Front right (−)
7	Rear right (+)
8	Rear right (−)
15	Ground
16	Battery positive

CAN and telephone

Pin	Signal
1	CAN high
2	CAN low
3	Antenna supply
4	Wake-up
5	Telephone mute

Serial interface

Pin	Signal
6	UART TX
12	UART RX

Mercedes-Benz COMAND (2003-2006) Head Unit

for W208 - W210

Connector overview

Power and control

Pin	Signal
1	—
2	K-line diagnostics
3	Telephone mute
4	Battery positive (30)
5	Antenna enable
6	—
7	Switched supply (15)
8	Ground (31)

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

Video and accessory

Pin	Signal
1	Video ground
2	RGB sync
3	Battery supply (30)
4	Ground (31)
5	RGB ground
6	Blue video
7	Green video
8	Red video

18-pin accessory

Pin	Signal
1	—
2	TV audio right
3	TV audio ground
4	AUX right
5	AUX right ground
6	—
7	—
8	CAN low
9	CAN high
10	Wake-up
11	TV audio left
12	TV audio shield
13	AUX left
14	AUX shield
15	Reverse
16	—
17	Navigation CAN low
18	Navigation CAN high

Mercedes-Benz COMAND 2

Connector overview

Power and control

Pin	Signal
1	Speed pulse
2	K-line diagnostics
3	Telephone mute
4	Battery positive (30)
5	Antenna enable
6	Illumination
7	Switched supply (15)
8	Ground (31)

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

Video and accessory

Pin	Signal
1	RGB audio ground
2	RGB sync
3	CD changer supply
4	CD changer ground
5	RGB ground
6	Blue video
7	Green video
8	Red video

18-pin accessory

Pin	Signal
1	CAN wake-up
2	TV audio right
3	TV audio ground
4	AUX right
5	AUX right ground
6	Speed pulse
7	Interior CAN shield
8	Interior CAN low
9	Interior CAN high
10	D2B wake-up
11	TV audio left
12	TV audio shield
13	AUX left
14	AUX shield
15	Reverse
16	Navigation CAN shield
17	Navigation CAN low
18	Navigation CAN high

Mercedes-Benz COMAND 2 W163 (2001-2005) Head Unit

p/n A 163 820 36 89

Connector overview

Power and control

Pin	Signal
1	DF
2	K-line diagnostics
3	Telephone mute
4	Battery positive (30)
5	Antenna enable
6	Illumination
7	Switched supply (15)
8	Ground (31)

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

Video and accessory

Pin	Signal
1	Video ground
2	RGB sync
3	Battery supply (30)
4	Ground (31)
5	RGB ground
6	Blue video
7	Green video
8	Red video

18-pin accessory

Pin	Signal
1	—
2	TV audio right
3	TV audio ground
4	AUX right
5	AUX right ground
6	—
7	—
8	—
9	—
10	Wake-up
11	TV audio left
12	TV audio shield
13	AUX left
14	AUX shield
15	Reverse
16	—
17	Navigation CAN low
18	Navigation CAN high

Mercedes-Benz COMAND 2 W203, S203, CL203, W639, V639 (2000-2004) Head Unit

p/n A 203 820 96 89 80

Connector overview

Power and control

Pin	Signal
1	DF
2	K-line diagnostics
3	Telephone mute
4	Battery positive (30)
5	Antenna enable
6	—
7	—
8	Ground (31)

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

Video and accessory

Pin	Signal
1	Video ground
2	RGB sync
3	Battery supply (30)
4	Ground (31)
5	RGB ground
6	Blue video
7	Green video
8	Red video

18-pin accessory

Pin	Signal
1	—
2	TV audio right
3	TV audio ground
4	AUX right
5	AUX right ground
6	Right wheel speed
7	—
8	Interior CAN low
9	Interior CAN high
10	Wake-up
11	TV audio left
12	TV audio shield
13	AUX left
14	AUX shield
15	Reverse
16	—
17	Navigation CAN low
18	Navigation CAN high

Mercedes-Benz COMAND 2.5 (code 512,527,528)

Connector overview

Master connector reference · 40-pin Quadlock radio socket

Quadlock block A

Pin	Signal
1	RR+
2	FR+
3	FL+
4	RL+
5	RR-
6	FR-
7	FL-
8	RL-
9	CAN B Low
10	Telephone Mute
11	CAN-B High
12	U-Bat- (KL 31)
13	reserved
14	CAN-B shield
15	U-Bat+ (KL 30)
16	Electrical MOST Wake-Up

Quadlock block B

Pin	Signal
1	Microphone 1 In +
2	Microphone 2 In +
3	Microphone Shield
4	Microphone Out+
5	HU CAN low
6	HU Can High
7	Cradle compensator On
8	reserved
9	Microphone Ground
10	Microphone out -
11	reserved
12	reserved

Quadlock block C

Pin	Signal
1	reserved
2	Ext FAN power supply -
3	Aux1 shield
4	Aux1 left
5	reserved
6	reserved
7	Ext FAN diagnosis line
8	Ext FAN power supply +
9	Aux1 ground
10	Aux1 right
11	reserved
12	reserved

Quadlock block D

Pin	Signal
1	MOST optical receive
2	MOST optical transmit

Japan · white MQS connector

Pin	Signal
1	ETC Rx
2	ETC Tx
3	ETC shield
4	VICS Rx
5	VICS Tx
6	VICS shield
7	ETC GND
8	ETC ON (12V)
9	reserved
10	VICS GND
11	VICS power (+5V)
12	reserved

Japan · blue MQS connector

Pin	Signal
1	Serial Tx+
2	Serial Tx-
3	Serial Rx-
4	Serial Rx+
5	Voice to Tel (DTR)
6	Voice from Tel (DCD)
7	CTS
8	RTS
9	GND
10	Power (12V)
11	Remote
12	Shield Voice Tel

18-pin MQS · video and AUX 2

Pin	Signal
1	Video in CVBS (ECE, USA) or Video in Y (Japan)
2	Video in Ground (ECE, USA) or Video in Y ground (Japan)
3	Audio out Ground
4	Audio out right
5	Video out CVBS
6	Video out CVBS shield
7	reserved
8	Aux2 ground
9	Aux2 in left
10	reserved (ECE, USA) or Video in C (Japan)
11	reserved (ECE, USA) or Video in C ground (Japan)
12	Audio out shield
13	Audio out left
14	reserved
15	reserved
16	reserved
17	Aux2 shield
18	Aux2 in right

Mercedes-Benz COMAND 2.5 (Typ 220)

Connector overview

Power and control

Pin	Signal
1	—
2	Ground (31)
3	Antenna enable
4	—
5	Telephone mute
6	Battery supply (30)
7	Battery supply (30)
8	Ground (31)

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

Audio input

Pin	Signal
3	Right audio
4	Ground
7	Left audio
8	Audio signal

Navigation and CAN

Pin	Signal
1	K-line diagnostics
2	Navigation link E/21
3	Navigation link E/22
4	Navigation link E/23
5	Navigation audio E/26
6	Navigation audio E/25
7	Wake-up
11	Navigation link E/9
12	Navigation link E/10
13	Navigation audio E/13
14	Left audio
15	CAN low
16	CAN high
17	Navigation CAN low
18	Navigation CAN high

Mercedes-Benz Comand APS NTG4.5 Radio Navigation Head Unit

Connector overview

Master connector reference · 40-pin Quadlock radio socket

Block A · power, speakers and CAN

Pin	Signal
1	Rear right (+)
2	Front right (+)
3	Front left (+)
4	Rear left (+)
5	Rear right (−)
6	Front right (−)
7	Front left (−)
8	Rear left (−)
9	Body CAN low
10	NC on COMAND / mute on Audio 20
11	Body CAN high
12	Ground (31)
13	Cradle or compensator enable
14	—
15	Battery positive (30)
16	Wake-up

Block B · microphones, AUX and CAN

Pin	Signal
1	Microphone 1 (+)
2	Microphone shield
3	Microphone output (+)
4	AUX left
5	AUX shield
6	Head unit CAN low
7	Microphone 2 (+)
8	Microphone ground
9	Microphone output (−)
10	AUX right
11	AUX ground
12	Head unit CAN high

Block C · external fan

Pin	Signal
1	Fan control
2	Fan supply (−)
3	—
4	—
7	Fan diagnostics
8	Fan supply (+)

Block D · MOST

Pin	Signal
1	Optical receive
2	Optical transmit
3	NC
4	NC

Mercedes-Benz Comand NTG4.0 Fakra Quadlock Radio Stereo

W212, W245 (2010-2011)

Connector overview

Master connector reference · 40-pin Quadlock radio socket

Main Quadlock

Pin	Signal
1	Rear right (+)
2	Front right (+)
3	Front left (+)
4	Rear left (+)
5	Rear right (−)
6	Front right (−)
7	Front left (−)
8	Rear left (−)
9	Body CAN low
10	Telephone mute
11	Body CAN high
12	Ground (31)
13	Antenna enable
14	—
15	Battery positive (30)
16	Wake-up

Accessory · fan and AUX

Pin	Signal
1	Fan supply (−)
2	—
3	—
4	—
5	AUX shield
6	AUX left
7	Fan supply (+)
8	—
9	—
10	—
11	AUX ground
12	AUX right

Telephone and serial interface

Pin	Signal
1	Voice audio (+)
2	Voice audio (−)
3	Audio ground
4	Microphone mute
5	Telephone interface wake-up
6	UART RX shield
7	UART RX (+)
8	UART RX (−)
9	UART TX shield
10	UART TX (+)
11	UART TX (−)

MOST fibre

Pin	Signal
1	Optical receive
2	Optical transmit

Mercedes-Benz Truckline CC40 (1998-2005) Tape Head Unit

p/n A0048200386, YU3F-18C838-BA

Connector overview

Power and control

Pin	Signal
4	Battery positive
5	Antenna enable
6	Illumination
7	ACC
8	Ground

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

Mercedes-Benz W203, S203, CL203 (2000-2007) Audio 20 MF2530 Head Unit

p/n A 203 827 38 42, A 203 870 05 89, A 203 870 50 89, A 203 870 36 89

Connector overview

Master connector reference · 40-pin Quadlock radio socket

Main Quadlock

Pin	Signal
1	Rear right (+)
2	Front right (+)
3	Front left (+)
4	Rear left (+)
5	Rear right (−)
6	Front right (−)
7	Front left (−)
8	Rear left (−)
9	I-BUS
10	Telephone mute
11	Telephone enable
12	Ground
13	Antenna enable
14	Illumination
15	Battery positive
16	ACC

Mercedes-Benz W204 Car Stereo

Connector overview

Master connector reference · 40-pin Quadlock radio socket

Block A · main Quadlock

Pin	Signal
1	Rear right (+)
2	Front right (+)
3	Front left (+)
4	Rear left (+)
5	Rear right (−)
6	Front right (−)
7	Front left (−)
8	Rear left (−)
9	Body CAN low
10	Mute on Audio 20 only
11	Body CAN high
12	Ground (31)
13	Cradle or compensator enable
14	—
15	Battery positive (30)
16	Wake-up

Block B · microphone and AUX

Pin	Signal
1	Microphone 1 (+)
2	Microphone 2 (+)
3	Microphone shield
4	Microphone out (+)
5	AUX shield
6	AUX left
7	—
8	—
9	Microphone ground
10	Microphone out (−)
11	AUX ground
12	AUX right

Block C · fan and CAN

Pin	Signal
1	Fan control
2	Fan supply (−)
3	—
4	—
5	Head unit CAN low
6	Head unit CAN high
7	Fan diagnostics
8	Fan supply (+)

Block D · MOST

Pin	Signal
1	Optical receive
2	Optical transmit
3	NC
4	NC

Block E · display LVDS

Pin	Signal
1	Data 2 (−)
2	Data 2 (+)
3	Clock (−)
4	Clock (+)
5	Ground
6	Data 1 (+)
7	Data 1 (−)
8	Data 0 (+)
9	Data 0 (−)
10	Ground

Mercedes-Benz W220 · TV tuner and rear display

Connector overview

A · power and control

Pin	Signal
1	Speed pulse
2	K-line
3	—
4	Battery positive (30)
5	12 V output
6	Illumination (58)
7	Switched supply (15)
8	Ground (31)

B · rear display video

Pin	Signal
1	Red ground
2	Red
3	Green ground
4	Green
5	Blue ground
6	Blue
7	Sync ground
8	Sync

C · rear display audio and control

Pin	Signal
1	TV audio right
2	TV audio left
3	TV audio ground
4	Rear display supply (+)
5	Rear display supply (−)
6	Bus ground
7	F-Bus C
8	F-Bus D
9	Remote signal
10	Remote ground

D · COMAND link

Pin	Signal
1	Sync
2	Blue
3	Green
4	Red
5	Ground
6	Bus high
7	Bus ground
8	Audio ground
9	Left audio
10	Sync ground
11	Blue ground
12	Green ground
13	Red ground
14	Bus ground
15	Bus low
16	Bus ground
17	Audio ground
18	Right audio

E · AV-1 input

Pin	Signal
1	Composite video
2	Bus ground
3	Remote control
4	—
5	Audio ground
6	Left audio
7	Composite ground
8	—
9	Remote ground
10	—
11	Audio ground
12	Right audio

F · AV-2 input

Pin	Signal
1	Composite / luminance
2	Bus ground
3	Remote control
4	—
5	Audio ground
6	Left audio
7	Composite ground
8	Chrominance
9	Remote ground
10	—
11	Audio ground
12	Right audio

Smart

Smart RADIO, RADIO CC

Connector overview

Power and control

Pin	Signal
1	Climate link
3	KLTG diagnostic line
4	Switched supply (15)
5	Antenna enable
6	Illumination
7	Battery positive (30)
8	Ground

Speakers

Pin	Signal
1	Rear left (+)
2	Rear left (−)
3	Right door (+)
4	Right door (−)
5	Left door (+)
6	Left door (−)
7	Rear right (+)
8	Rear right (−)

Smart 999cc Fortwo car stereo

Visteon radio 9 i 10

Connector overview

Power and control

Pin	Signal	Wire colour
1	Illumination from speedometer pin 12	Grey / blue
2	NC
3	Switched 12 V	Black / grey
4	Permanent 12 V, sub pin 3	Red / blue
5	Remote output, sub pin 8	Black
6	NC
7	NC
8	Ground	Brown

Speakers

Pin	Signal	Wire colour
1	Right tweeter (+), sub pin 5	Blue
2	Right tweeter (−), sub pin 2	Blue / brown
3	Right speaker (+)	Orange
4	Right speaker (−)	Brown / orange
5	Left speaker (+), sub pin 4	Green
6	Left speaker (−), sub pin 1	Brown / green
7	Left tweeter (+)	Yellow
8	Left tweeter (−)	Yellow / brown

Accessory

Pin	Signal	Wire colour
1	Line in left	Violet
2	Line in right	Green
3	Line ground	Black
4	Mute	Yellow
5	Switched supply	Blue
6	Permanent supply	Red
7	Ground	Brown

Smart Audio 20 Quadlock connector

Connector overview

CAN in the 12-pin insert

Master connector reference · 40-pin Quadlock radio socket

CAN in the main block

Master connector reference · 40-pin Quadlock radio socket

Variant with CAN in the 12-pin insert · main

Pin	Signal
1	Front left (+)
2	Front left (−)
3	Rear left (+)
4	Rear left (−)
5	Front right (+)
6	Front right (−)
7	Rear right (+)
8	Rear right (−)
15	Ground (31)
16	Battery positive (30)

Variant with CAN in the 12-pin insert · CAN

Pin	Signal
1	CAN high
2	CAN low
3	Antenna enable
4	Wake-up
5	Telephone mute

Variant with CAN in the main block · main

Pin	Signal
1	Rear right (+)
2	Front right (+)
3	Front left (+)
4	Rear left (+)
5	Rear right (−)
6	Front right (−)
7	Front left (−)
8	Rear left (−)
9	CAN low
10	Mute
11	CAN high
12	Ground (31)
13	Antenna enable
14	Not busy
15	Battery positive (30)
16	Wake-up

Variant with CAN in the main block · AUX

Pin	Signal
5	Ground
6	AUX left
11	AUX ground
12	AUX right

Smart Comand Head Unit

Connector overview

Power and control

Pin	Signal
1	Speed pulse
2	K-line diagnostics
3	Telephone mute
4	Battery positive (30)
5	Antenna enable
6	Illumination
7	Switched supply (15)
8	Ground (31)

Speakers

Pin	Signal
1	Rear right (+)
2	Rear right (−)
3	Front right (+)
4	Front right (−)
5	Front left (+)
6	Front left (−)
7	Rear left (+)
8	Rear left (−)

Video and accessory

Pin	Signal
1	TV red
2	TV green
3	TV blue
5	CD changer ground
6	CD changer supply

18-pin accessory

Pin	Signal
1	CAN wake-up
2	TV audio right
3	TV audio ground
4	AUX right
5	AUX right ground
6	Speed pulse
7	Interior CAN shield
8	Interior CAN low
9	Interior CAN high
10	D2B wake-up
11	TV audio left
12	TV audio shield
13	AUX left
14	AUX shield
15	Reverse
16	Navigation CAN shield
17	Navigation CAN low
18	Navigation CAN high

Smart Forfour car stereo

Harman Becker Radio 5

Connector overview

Power and control

Pin	Signal	Wire colour
1	Hands-free module	Green / red
2	NC
3	Hands-free module	Black / blue
4	Permanent 12 V, sub pin 3	Red / black
5	Remote output, sub pin 8	White
6	LIN voltage	Brown / red
7	12 V	Brown
8	Ground	Black

Speakers

Pin	Signal	Wire colour
1	Rear right (+)	Yellow / red
2	Rear right (−), sub pin 5	Grey / red
3	Right door and tweeter (+), sub pin 2	White / red
4	Right door and tweeter (−)	Black / red
5	Left door and tweeter (+), sub pin 1	White / blue
6	Left door and tweeter (−)	Brown / green
7	Rear left (+)	Yellow / blue
8	Rear left (−), sub pin 4	Grey

Accessory

Pin	Signal	Wire colour
1	Line in left	White
2	Line in right	Brown
3	Line ground	Shield

Smart Fortwo 450, Roadster car stereo · Grundig

Grundig

Connector overview

Power and control

Pin	Signal	Wire colour
1	NC
2	NC
3	NC
4	Switched 12 V	Blue
5	Remote output
6	Illumination	Brown / white or green / blue
7	Permanent 12 V	Pink / white or pink
8	Ground	Brown

Speakers

Pin	Signal	Wire colour
1	Right tweeter (+)	Yellow
2	Right tweeter (−)	Yellow / black
3	Right speaker (+)	Green / yellow
4	Right speaker (−)	Grey / green
5	Left speaker (+)	Green / blue
6	Left speaker (−)	Grey / brown
7	Left tweeter (+)	Green
8	Left tweeter (−)	Green / black

Accessory

Pin	Signal
1	NC
2	NC
3	NC
4	NC
5	NC
6	Permanent 12 V
7	Switched 12 V
8	Mute
9	Ground
10	Illumination 12 V
11	Telephone speaker (+)
12	Telephone speaker (−)
13	CD changer signal
14	NC
15	Ground
16	Permanent 12 V
17	Switched 12 V
18	CD changer input (−)
19	CD changer left
20	CD changer right

Smart Fortwo 450, Roadster car stereo · Becker BE6040

Becker Navigation and Sound BE6040

Connector overview

Power and control

Pin	Signal
1	Speed pulse
2	K-line
3	Mute
4	Permanent 12 V
5	Remote output
6	Illumination
7	Switched 12 V
8	Ground

Speakers

Pin	Signal
1	Right tweeter (+)
2	Right tweeter (−)
3	Right speaker (+)
4	Right speaker (−)
5	Left speaker (+)
6	Left speaker (−)
7	Left tweeter (+)
8	Left tweeter (−)

Accessory

Pin	Signal
1	CAN high
2	CAN low
3	Reverse
4	Wake-up
5	Permanent 12 V output
6	Ground

GPS antenna

Pin	Signal
1	GPS antenna