Audio HU1205

Fig 1: Audio HU1205 (Audio Module)

Courtesy of VOLVO CARS OF NORTH AMERICA.

HINT: All values listed below are measured between the respective terminal in column 1 (control module terminal) and terminal A12 (power ground) unless stated otherwise in column 6 (Other).

NOTE:

It is important to read about breakout box connection and checking ground terminals before readings are taken. See Connecting the breakout box, Audio HU1205 (audio module) .

U = DC voltage in volts (V)	Ubat = Battery voltage (V)
I = Current in amperes (A)	Ulow = Voltage close to 0 V
f = Frequency in Hertz (Hz)	%duty = Duty cycle (pulse ratio) as a percentage (%)
t = time in milliseconds (ms)	UAC = AC voltage in volts

Fig 2: Connector End View -- Connector B1

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Control module terminal	Breakout box terminal	Signal type	Ignition off	Ignition on	Other
A1	#15	30 supply	U = Ubat	Ubat	-
A2	#16	15 supply	U = Ulow	Ubat	-
A3	#17	Rheostat signal (+), input signal	-	PWM signal Umin= Ulow Umax=12 V f=130Hz	Signal from the central electronic module (CEM). An increased pulse ratio gives greater luminance. (If there is no rheostat signal, there will be maximum luminance in the audio module)
A4	#18	Speed signal, input signal	-	Pulsed signal Umin= Ulow Umax=12 V	Pulsed signal from the combined instrument panel. Frequency increases with increase in speed.
A5	#19	Back-up (reversing) lamp switch, input signal	-	Back-up (reversing) lamp switch activated: U = Ubat back-up (reversing) lamp switch not activated: U = Ulow	The back-up (reversing) lamp switch must be activated when reverse gear is engaged.
A6	#20	Carphone mute, input signal	-	During telephone calls (mute): U=Ulow when there is no ongoing call (not muted): U =5 V	A carphone with mute function can be connected. Lowers the volume of the audio source during telephone calls.
A7	#21	-	-	-	-
A8	#22	Power ground	U = Ulow	U = Ulow	Measured to battery negative terminal
A9	#23	Remote control signal ON/OFF	U = Ulow	Audio unit ON: U = Ubat OFF: U = Ulow	Remote control: antenna amplifier , Bass speaker (Integrated power stage).
A10	#24	-	-	-	-
A11	#25	-	-	-
A12	#26	Power ground	U = Ulow	U = Ulow	Measured to battery negative terminal

Fig 3: Connector End View -- Connector B1

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Control module terminal	Breakout box terminal	Signal type	Ignition off	Ignition on	Other
B1	#1	Audio channel (+), loudspeaker left front	U = Ulow	Alternating current when sound at front left loudspeaker	(measured to terminal #B2)
B2	#2	Audio channel (-), loudspeaker left front	U = Ulow	Alternating current when sound at front left loudspeaker	(measured to terminal #B1)
B3	#3	-	-	-	-
B4	#4	-	-	-	-
B5	#5	Audio channel (+), loudspeaker right front	U = Ulow	Alternating current when sound at front right loudspeaker	(measured to terminal #B6)
B6	#6	Audio channel (-), loudspeaker right front	U = Ulow	Alternating current when sound at front right loudspeaker	(measured to terminal #B5)
B7	#7	Audio channel (+), loudspeaker left rear	U = Ulow	Alternating current when sound at left rear loudspeaker	(measured to terminal #B8)
B8	#8	Audio channel (-), loudspeaker left rear	U = Ulow	Alternating current when sound at left rear loudspeaker	(measured to terminal #B7)
B9	#9	-	-	-	-
B10	#10	-	-	-	-
B11	#11	Audio channel (+), loudspeaker right rear	U = Ulow	Alternating current when sound at right rear loudspeaker	(measured to terminal #B12)
B12	#12	Audio channel (-), loudspeaker right rear	U = Ulow	Alternating current when sound at right rear loudspeaker	(measured to terminal #B11)

Fig 4: Connector End View -- Connector B1

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NOTE:

Adapter 9511509 must also be connected to the breakout box in order to check the following signals.

Control module terminal	Breakout box terminal	Signal type	Ignition off	Ignition on	Other
D1	#16	Clock signal, Communication cable	-	Digital signal	Communication cable between the audio unit and the CD changer
D2	#17	Signal ground, sound	-	Alternating current when there is sound	-
D3	#18	Remote control signal, CD changer	U = Ulow	U = Ubat	Signal from the audio unit to the CD changer
D4	#19	Data signal, Communication cable	-	Digital signal	Communication cable between the audio unit and the CD changer
D5	#20	Busy signal, Communication cable	-	Digital signal	Communication cable between the audio unit and the CD changer
D6	#21	Left audio signal (+), input signal	-	Alternating current when there is sound	Signal from the CD changer to the audio unit. Measured to terminal #D2
D7	22	Right audio signal (+), input signal	-	Alternating current when there is sound	Signal from the CD changer to the audio unit. Measured to terminal #D2
D8	23	Voice guide channel	-	Alternating with sound (voice guiding) from the audio unit	Signal from the audio unit to the CD changer. Measured to terminal #D2
Connector casing	-	Screening for the cable for the CD changer	-	-	-

Fig 5: Connector End View -- Connector C1 & C2

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Control module terminal	Breakout box terminal	Signal type	Ignition off	Ignition on	Other
C1	-	Antenna signal, head antenna	-	-	Analog signal
C2	-	-	-	-	-

Fig 6: Connector End View -- Connector E1

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Control module terminal	Breakout box terminal	Signal type	Ignition off	Ignition on	Other
E1	-	Antenna signal, GPS antenna	-	Audio unit ON: U=5 V direct current, the GPS antenna signal is a superimposed alternating current	Measured to the connector casing (screening)