AUDI A4 1999 B5 / 1.G Brakes Read Mesure Value Block Owner's Manual

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

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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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.8

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
)
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

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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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.8

1) Only for vehicles with Front Wheel Drive (FWD) and ABS/EDL Bosch 5 2) Only for vehicles with Front Wheel Drive (FWD) and ABS/ASR Bosch 5 3) Only for vehicles with All Wheel Drive (AWD) and ABS/EDL Bosch 5, (ABS) pressure regulation 4) Only for vehicles with Front Wheel Drive (FWD) and ABS Bosch 5 5) Only for vehicles with All Wheel Drive (AWD) and ABS/EDL Bosch 5, throttle valve regulation
Pa
ge 25 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

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
)
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

01-80

Function test
Test
step VAG
1598/20
sockets Test of
Test requirements
- Additional work stepsSpecified
value Corrective action
13
1)
Bridge
1 + 2,
28 + 37 Inlet valve -
N101 and front
left brake line
connection
Ignition on

- for vehicles with
automatic
transmission, engage
neutral position "N"
- Bridge terminals 5 +
28
- Depress brake pedal
and hold.





Left front
wheel can
be rotated
by hand - If the wheel does not rotate, check the
other wheels for free rotation. If yes, then
hydraulic brake lines are mixed-up
(switched). Check brake line connections
and coupling pieces. Make sure every
component is OK. Repeat test step 13.
- If all wheels are blocked, inlet valve is
malfunctioning DTC table page 01
-98
,
DTC 00257.

- Remove bridge 5 +
28.
The left-
front wheel
remains
Pa
ge 27 of 79 Read Measurin
g Value Block
(function 08
)
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yp
e=re
pair&id=AUDI.B5.SU02.01.8

locked.

- Release brake pedal.
1) This test step requires two technicians.
Pa
ge 28 of 79 Read Measurin
g Value Block
(function 08
)
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yp
e=re
pair&id=AUDI.B5.SU02.01.8

01-81

Function test
Test
step VAG
1598/20
sockets Test of
Test requirements
- Additional work stepsSpecified
value Corrective action
14
1)
Bridge
1 + 2,
28 + 37 Inlet valve -N99-
and front right
brake line
connection
Ignition on

- for vehicles with
automatic
transmission, engage
neutral position "N"
- Bridge terminals 54 +
28
- Depress brake pedal
and hold.





Right front
wheel can
be rotated
by hand - If the wheel does not rotate, check the
other wheels for free rotation. If yes, then
hydraulic brake lines are mixed-up
(switched). Check brake line connections
and coupling pieces. Make sure every
component is OK. Repeat test step 14.
- If all wheels are blocked, inlet valve is
malfunctioning DTC table page 01
-98
,
DTC 00259.

- Remove bridge 54 +
28.
The right-
front wheel
remains
Pa
ge 29 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

locked.

- Release brake pedal.
1) This test step requires two technicians.
Pa
ge 30 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