1999 AUDI A4 brake

locked.

- Release brake pedal.
1) This test step requires two technicians.
Pa
ge 30 of 79 Read Measurin
g Value Block
(function 08
)
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yp
e=re
pair&id=AUDI.B5.SU02.01.8

01-82

Function test
Test
step VAG
1598/20
sockets Test of
Test requirements
- Additional work stepsSpecified
value Corrective action
15
1)
Bridge
1 + 2,
28 + 37 Inlet valve -
N134- and rear
left brake line
connection
Ignition on

- for vehicles with
automatic
transmission, engage
neutral position "N"
- Bridge terminals 53 +
28
- Depress brake pedal
and hold.





Left rear
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 15.
- If all wheels are blocked, inlet valve is
malfunctioning DTC table page 01
-98
,
DTC 00274.

- Remove bridge 53 +
28.
The left-
rear wheel
remains
Pa
ge 31 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 32 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

01-83

Test
step VAG
1598/20
sockets Test of
Test requirements
- Additional work stepsSpecified
value Corrective action
16
1)
Bridge
1 + 2,
28 + 37 Inlet valve -
N133- and rear
right brake line
connection
Ignition on

- for vehicles with
automatic
transmission, engage
neutral position "N"
- Bridge terminals 6 +
28
- Depress brake pedal
and hold.





Right rear
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 16.
- If all wheels are blocked, inlet valve is
malfunctioning DTC table page 01
-98
,
DTC 00273.

- Remove bridge 6 +
28.
The right-
rear wheel
remains
locked.
Pa
ge 33 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

- Release brake pedal.
1) This test step requires two technicians.
Pa
ge 34 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

01-84

Function test and check for proper seal
Test
step VAG
1598/20
sockets Test of
Test requirements
- Additional work stepsSpecified value
Corrective action
17 Bridge
1 + 2,
7 + 37,
37 + 28
ABS return
flow pump -
V39-
Left front
traction
control
switch-over
valve -N168-
Left front
traction
control outlet
valve -N169- Repair Manual,
Brake System, Repair Group 47
- Connect VAG1310A
pressure gauge to front
left brake caliper and
bleed.
- Bridge terminals 3 +
28
Repair Manual, Brake System,
Repair Group 45
- ABS return flow pump
malfunctioning, replace ABS
hydraulic unit -N55-


Pressure
relief valve in
ABS hydraulic
unit -N55-
Left front ABS
outlet valve -
N102- - Switch on ignition for
max. 10 seconds and
switch off again.
Left front
traction control
switch-over
valve -N168-
switched ABS return
flow pump -
V39- runs Pressure on
pressure - Check left front traction control
switch-over valve -N168- and left
front traction control outlet valve -
N169- via resistance test test steps
5 + 6. Replace ABS hydraulic unit -
N55- if malfunctioning.
Pa
ge 35 of 79 Read Measurin
g Value Block
(function 08
)
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yp
e=re
pair&id=AUDI.B5.SU02.01.8

01-85

Function test and check for proper seal
Test step
VAG
1598/20
sockets Test of
Test requirements
- Additional work
steps Specified value
Corrective action
17

Continuation:

Right rear
ABS
outlet
valve -
N135- - Bridge terminals 4 +
28
- Switch on ignition for
max. 10 seconds and
switch off again.
Front Wheel Drive
(FWD):
170 25 bar
All-Wheel Drive
(AWD), pressure
regulation (ABS):
90 25 bar
Left front
traction control
outlet valve -
N169- switchedPressure
increases on
pressure
gauge:
- Pressure relief valve and/or left
front ABS outlet valve -N102-
and/or right rear ABS outlet valve
-N135- malfunctioning. Replace
ABS hydraulic unit -N55-.

- Remove VAG1310A
pressure gauge and
bleed brakes All Wheel Drive
(AWD), throttle
valve regulation:
170 25 bar

Pa
ge 37 of 79 Read Measurin
g Value Block
(function 08
)
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yp
e=re
pair&id=AUDI.B5.SU02.01.8

Repair Manual,
Brake System, Repair Group 47

Pa
ge 38 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