wiring diagram AUDI A4 1995 B5 / 1.G Brakes Read Mesure Value Block Workshop Manual
Page 7 of 79
0   Brake pedal not operated1   Brake pedal operated
  
 Electrical Wiring Diagrams, Troubleshooting & Component 
Locations    - Check brake light switch if there are deviations.
Brake light switch: Signal for Front 
and All Wheel Drive:  
 
0   Brake pedal not operated  1   Brake pedal operated 
  
  
 Electrical Wiring Diagrams, Troubleshooting & Component Locations    - Check brake light switch if there are deviations.
Pa
ge 7 of 79 Read Measurin
g Value Block 
(function 08
)
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Page 14 of 79
01-71
      
Connecting the VAG1598/20 test box and 
checking the ABS, ABS/EDL or ASR system  
     
-  Switch ignition off.
     
-  Remove ABS control module -J104-.
     
       Repair manual, Brake System, Repair Group 
45
   
     
-  Disconnect multi-pin connector from ABS control 
module -J104-. 
     
-  Check multi-pin connector between harness 
connector and ABS control module -J104-. 
    
The socket designations on the VAG1598/20 test box are identical to the 
terminal designations on the ABS control module -J104- and on the wiring 
harness connector.  
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   -  Connect VAG1598/20 test box to multi-pin connector of ABS wiring 
harness. 
Pa
ge 14 of 79 Read Measurin
g Value Block 
(function 08
)
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Page 21 of 79
01-75
 Notes:  
For test table: 
 
The socket designations of the VAG1598 test box are identical to the terminal designations of the ABS control module 
(w/EDL) -J104- in the wiring diagram. Incorrect test procedures can cause damage to the system. Do not bridge any 
terminals other than those listed in the table. 
 Electrical Wiring Diagrams, Troubleshooting & Component Locations    Specified values refer to readings on the VAG1526 and are not necessarily applicable for other test units.
 If the measured values do not match specifications, carry out the corrective actions listed on the right side of the table.
 Electrical Wiring Diagrams, Troubleshooting & Component Locations    If values are obtained, also check wiring for intermittent loose terminals and short circuit to B+ and Ground (GND). This 
applies especially to sporadic malfunctions. 
 Use the VAG1594 connector test kit for checking continuity (bridges).
 If the measured values only differ slightly from the specifications, clean the sockets and harness connectors of the testers 
and adapter leads (using contact spray G 000 700 04) and repeat the test. Before replacing actual components, check 
wiring and connections once more. This is especially important if the specification for a resistance test is under 10  . 
Pa
ge 21 of 79 Read Measurin
g Value Block 
(function 08
)
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yp
e=re
pair&id=AUDI.B5.SU02.01.8 
Page 22 of 79
01-76
 
Resistance measurement: Select measurement range on VAG1526 (200  )  Test 
step  VAG  
1598/20 
sockets  Test of  
Test requirements 
- Additional work stepsSpecified 
value  Corrective action  
1   5 + 33   Left front ABS inlet 
valve -N101-, left 
front ABS outlet 
valve -N102-          
2   54 + 26   Right front ABS inlet 
valve -N99-, right 
front ABS outlet 
valve -N100-  Electrical wiring 
between control module 
and hydraulic unit OK 9 22
  
- Check electrical wiring between 
control module and hydraulic unit for 
short circuit to Ground (GND) or B+ 
3   53 + 25   Inlet valve -N134-, 
outlet valve -N136- 
left-rear         Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations   
4   6 + 34   Inlet valve -N133-, 
outlet valve -N135- 
right-rear       
- If the electrical wiring is OK, 
replace the hydraulic unit. 
Pa
ge 22 of 79 Read Measurin
g Value Block 
(function 08
)
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yp
e=re
pair&id=AUDI.B5.SU02.01.8 
Page 23 of 79
01-77
 
Resistance measurement: Select measurement range on VAG1526 (200  )  
Test step  
VAG  
1598/20 
sockets  Test of  
Test requirements 
- Additional work steps Specified 
value  Corrective action  
5  
Note:  
Only for 
vehicles with 
ABS/EDL or 
ASR  3 + 55   Left front traction 
control switch-over 
valve -N168- 
(secondary piston 
circuit)  
Right front traction 
control switch-over 
valve -N166- (primary 
piston circuit)  Electrical wiring 
between control 
module and hydraulic 
unit OK 12  
28   
 Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations    - Check electrical wiring 
between control module and 
hydraulic unit for short circuit 
to Ground (GND) or B+. - If the electrical wiring is OK, 
replace the hydraulic unit. 
6  
Note:  
Only for 
vehicles with 
ABS/EDL or 
ASR  4 + 27   Left front traction 
control outlet valve -
N169- (secondary 
piston circuit)  
Right front traction 
control outlet valve -
N167- (primary piston 
circuit)  
Electrical wiring 
between control 
module and hydraulic 
unit OK 12  
28   
 Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations    - Check electrical wiring 
between control module and 
hydraulic unit for short circuit 
to Ground (GND) or B+. - If the electrical wiring is OK, 
replace the hydraulic unit. 
Pa
ge 23 of 79 Read Measurin
g Value Block 
(function 08
)
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.8 
Page 24 of 79
01-78
 
Resistance measurement: Select measurement range on VAG1526 (2k  or 20 k )  Test 
step  VAG  
1598/20 
sockets  Test of  
Test requirements 
- Additional work stepsSpecified 
value  Corrective action  
7  
9 + 10 
1) 
2)  
35 + 10 
3) 
5)  
36 + 10 
4)  Left front ABS 
wheel speed 
sensor -G47-       
- Check electrical wiring between 
control module and wheel speed 
sensor for short circuit to Ground 
(GND) or B+ 
8  
15 + 14 1) 
3) 4)  
42 + 14 2) 
5)  Right front 
ABS wheel 
speed sensor 
-G45-  
Electrical wiring between 
control module and 
wheel speed sensor OK 400 2300   
 Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations   
9   13 + 12   Left rear ABS 
wheel speed 
sensor -G46-       
- If the electrical wiring is OK, 
replace the relevant ABS wheel 
speed sensor. 
10   11 + 38   Right rear 
ABS wheel 
speed sensor 
-G44-           Outlets on ABS control module -J104- differ depending on installed equipment
Pa
ge 24 of 79 Read Measurin
g Value Block 
(function 08
)
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Page 26 of 79
01-79
 
Resistance measurement: Select measurement range on VAG1526 (200  )  Test 
step  VAG  
1598/20 
sockets  Test of  
Test requirements 
- Additional work stepsSpecified 
value  Corrective action  
11   2 + 37   ABS solenoid 
valve relay -
J106-  Electrical wiring between 
control module and 
hydraulic unit OK 30  
80   
 Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations    - Check electrical wiring between 
control module and hydraulic unit for 
short circuit to Ground (GND) or B+. - If electrical wiring is OK, replace the 
relay. 
12   2 + 7   ABS return 
flow pump 
relay -J105-  
Electrical wiring between 
control module and 
hydraulic unit OK 30  
80   
 Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations    - Check electrical wiring between 
control module and hydraulic unit for 
short circuit to Ground (GND) or B+. - If electrical wiring is OK, replace the 
relay. 
Pa
ge 26 of 79 Read Measurin
g Value Block 
(function 08
)
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.8 
Page 44 of 79
01-89
 
Function test: ABS warning light -K47-  
Test step  
VAG  
1598/20 
sockets  Test of  
Test 
requirements 
- Additional work 
steps Specified value  
Corrective action  
19  
  
Continuation:  -   Function of 
ABS 
warning 
light -K47-  - Switch on 
ignition ABS warning 
light -K47- lights 
up for two (2) 
seconds and 
then goes out.  
 Electrical Wiring Diagrams, 
Troubleshooting & Component Locations    - If ABS warning light does not come on, 
check voltage of electrical system and test 
wiring from terminal 32 of ABS control 
module -J104- to instrument cluster for 
short circuit to Ground (GND). 
- The ABS warning lamp does not switch 
off after 2 seconds. The red "brake system 
malfunction" symbol lights up after 2 
seconds. Check wire from terminal 32 of 
ABS control module -J104- to instrument 
cluster for short circuit to B+ and open 
circuit. 
              
 Repair Manual, Electrical Equipment, 
Repair Group 90; Instrument cluster
    - Are both the vehicle voltage and the 
wiring from terminal 32 of ABS control 
module -J104- to the instrument cluster 
OK?   Malfunction in instrument cluster. Pa
ge 44 of 79 Read Measurin
g Value Block 
(function 08
)
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yp
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pair&id=AUDI.B5.SU02.01.8 
Page 48 of 79
01-93
 
Function test: Traction control indicator light -K86-. This is only installed if vehicle is equipped with ASR.  
Test step  
VAG  
1598/20 
sockets  Test of  
Test 
requirements 
- Additional work 
steps Specified value  
Corrective action  
21  
  
Continuation:  -   Function of 
traction 
control 
indicator light 
-K86-  - Switch on 
ignition Traction control 
indicator light -K86- 
comes on for two 
(2) seconds and 
then goes out.  
 Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations    - If traction control indicator light does 
not light up, check vehicle voltage and 
wire from terminal 31 of ABS control 
module -J104- to instrument cluster for 
short circuit to B+ and open circuit. 
- If traction control indicator lamp 
remains continuously lit, check wire 
from terminal 31 of ABS control 
module -J104- to instrument cluster for 
short circuit to Ground (GND). 
              
 Repair Manual, Electrical 
Equipment, Repair Group 90; Instrument cluster
    - Are both the vehicle voltage and the 
wiring from terminal 31 of ABS control 
module -J104- to the instrument 
cluster OK?   Malfunction in 
instrument cluster. 
Pa
ge 48 of 79 Read Measurin
g Value Block 
(function 08
)
11/20/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.8 
Page 50 of 79
01-95
 
Function test: Traction control button; set measurement range on VAG1526: 20 V =  
Test step  
VAG  
1598/20 
sockets  Test of  
Test requirements
- Additional work 
steps Specified 
value  Corrective action  
22   28 + 44   Function of 
traction control 
button  Ignition switched 
on.      
Continuation:        
- Traction control 
button not pressed 0.0 to 0.5 
V    
        
- Traction control 
button pressed 10.0 to 14.5 
V  
 Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations    - Check wire from terminal 28 to 
Ground (GND). 
- Check wire from terminal 44 to 
traction control button, terminal 6. 
- Check voltage supply from terminal 5 
of traction control button to terminal 15. 
- If no malfunctions can be found using 
the procedures in these steps, replace 
the traction control button. 
Pa
ge 50 of 79 Read Measurin
g Value Block 
(function 08
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.8