lock AUDI A4 1999 B5 / 1.G Radio System Workshop Manual
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Radio systems 
     
General information
 
     
CAUTION! 
     
Before working on the electrical system: 
     
Determine the correct coding for the anti-
theft radio. 
     Disconnect the battery Ground (GND) 
strap. 
     
Note:  
     After re-connecting the battery, activate the 
vehicle's electrical equipment (radio, clock, 
power windows, engine) according to the owner's 
manual. 
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8-pin connector II (brown)  6 - Switched positive supply (B+) for active speaker
8 - Clock signal
9 - Data signal
10 - Enable signal
12 - USA coding
13 - CD bus data (CD changer)
14 - CD bus clock (CD changer)
15 - Ground (GND) for (CD changer)
16 - Power supply (B+) (continuous)
17 - Switched positive supply (B+) for CD changer
18 - Low frequency Ground (GND) for CD changer
19 - Signal wire for left channel (CD low frequency-L)
20 - Signal wire for right channel (CD low frequency-R)
3 - Speaker line, right-front (+)
4 - Speaker line, right-front (-)
5 - Speaker line, left-front (+)
6 - Speaker line, left-front (-) 
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4 - Line out, left-front
5 - Line out, right-front
6 - Switched positive supply (B+) for BOSE amplifier
7 - BOSE coding
8 - Clock signal
9 - Data signal
10 - Enable signal
12 - USA coding
13 - CD bus data (CD changer)
14 - CD bus clock (CD changer)
15 - Ground (GND) (CD changer)
16 - Positive supply (B+) (continuous)
17 - Switched positive supply (B+) for CD changer
18 - Low frequency Ground (GND) for CD changer
19 - Signal wire for left channel (CD low frequency-L)
20 - Signal wire for right channel (CD low frequency-R)
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Multi-pin connectors I, II, III, IV (on back of 
radio), terminal assignments  
     
Note:  
     Terminals which are not listed are 
vacant/unassigned. 
    
20-pin connector I 
1 - Line out, left-rear
2 - Line out, right-rear
3 - Low frequency Ground (GND)
6 - Switched positive supply (B+) for active speaker (sedan) and/or 
subwoofer (Avant)
8 - Clock signal
9 - Data signal
10 - Enable signal
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8-pin connector II (brown)  13 - Bus data in (CD changer)
14 - Bus data out (CD changer)
15 - Clock (CD changer) 
16 - Continuous positive supply (B+)
17 - Switched positive supply (B+) (CD changer)
18 - Low frequency-Ground (GND) (CD changer)
19 - Signal wire for left channel (CD low frequency-L)
20 - Signal wire for right channel (CD low frequency-R)
3 - Speaker line, right-front (+)
4 - Speaker line, right-front (-)
5 - Speaker line, left-front (+)
6 - Speaker line, left-front (-) 
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8-pin connector II (brown)  8 - Clock signal
9 - Data signal
10 - Enable signal
13 - Bus data in (CD changer)
14 - Bus data out (CD changer)
15 - Clock (CD changer) 
16 - Continuous positive supply (B+)
17 - Switched positive supply (B+) (CD changer)
18 - Low frequency-Ground (GND) (CD changer)
19 - Signal wire left channel (CD low frequency-L)
20 - Signal wire right channel (CD low frequency-R)
5 - Hands-free speaker (+) 
6 - Hands-free speaker (-) 
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Removing  
      Perform the following work sequence:  
    
Remove radio release tools:  -  Insert T10057 radio removal tools into release slots (arrows) as shown 
until they engage. 
 
Top L - top and bottom left
 Top R - top and bottom right
-  Pull radio out of instrument panel using grip rings on release tool.
-  Unlock and disconnect harness connectors
    
Installing   -  Press locking latch arrow- and remove radio release tools toward front.
-  Connect harness connectors to radio.
-  Slide radio evenly into instrument panel, until it engages in assembly 
frame. 
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