1999 AUDI A4 brake

01-176

Set measurement range:
voltage test (20 V =)
Test
step VAG
1598
sockets Test of
Test requirements
- Additional work
steps Specified
value Corrective action
3 19 + 14 Function of brake
light switch -F- Ignition switched
off
- Check wire from terminal 19 to Ground
(GND).
Brake pedal not
depressed
- Operate brake pedal.0.0 -0.5 V

10.0 - 14.5
V
Electrical Wiring Diagrams,
Troubleshooting & Component Locations

Repair Manual, Brake System, Repair
Group 45
- Check wiring from terminal 14 to
terminal 30 via fuse (10A).
- Check brake light switch -F-
- Adjust brake light switch -F-.
Pa
ge 31 of 66 Out
put Dia
gnostic Test Mode
(DTM
) (function 03
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.13

01-180

Function test: ABS/EDL warning light -K47-
Test step
VAG
1598
sockets Test of
Test
requirements
- Additional work
steps Specified value
Corrective action
8

Continuation: - Function of
ABS/EDL
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/EDL warning light does not come
on, check voltage of electrical system and
test wiring from terminal 21 of ABS control
module -J104- to instrument cluster for
short circuit to Ground (GND).
- The ABS/EDL warning lamp does not
switch off after 2 seconds. The red "brake
system malfunction" symbol lights up after
2 seconds. Check wire from terminal 21 of
ABS control module -J104- to instrument
cluster for short circuit to B+ and open
circuit.

Repair Manual, Electrical Equipment,
Repair Group 90.
- If vehicle voltage and wire from terminal
21 of ABS control module -J104- to
instrument cluster are OK there is a
malfunction in instrument cluster, LED or
bulb malfunctioning.
Pa
ge 35 of 66 Out
put Dia
gnostic Test Mode
(DTM
) (function 03
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.13

01-181

Function test: Red brake warning symbol
Test
step VAG
1598
sockets Test of
Test requirements
- Additional work stepsSpecified
value Corrective
action
9 - Function of red "brake
system malfunction"
symbol
Repair Manual, Brake System, Repair
Group 47

Brake fluid level is OK Function of ABS warning light -K47-
already checked in step 8. Multi-pin connector connected to ABS
control module -J104- and retainer catch
engaged. Switch on ignition
Test step 9: Continued on
next page.
Pa
ge 36 of 66 Out
put Dia
gnostic Test Mode
(DTM
) (function 03
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.13

01-182

Function test: Red brake warning symbol
Test step
VAG
1598/20
sockets Test of
Test requirements
- Additional work stepsSpecified value
Corrective action
9

Continuation: Function of red
"brake system
malfunction"
symbol - Connect VAG1551 scan
tool and select address
word 03
- For vehicles with
automatic transmission and
high-line instrument cluster,
depress the brake pedal
and select a driving gear. The ABS indicator lamp
and the red "brake system
malfunction" symbol light
up. If the traction control
indicator light is installed
and OK, it also lights up. Repair Manual,
Electrical Equipment, Repair Group 90; instrument cluster.

- Malfunction in
instrument cluster
Pa
ge 37 of 66 Out
put Dia
gnostic Test Mode
(DTM
) (function 03
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.13

01-187
Diagnostic Trouble Code (DTC) table

Notes:

Fulfill test requirements page 01
-22
.
Connect the VAG1551 Scan Tool (ST) and select "Brake Electronics" via address word 03 page 01
-4 .
Check the control module version page 01
-128
and press the button.
Press buttons -0- and -2- to select "Check DTC Memory" function 02. Press -Q- button to confirm input.
Notes:
Each malfunction is assigned a 5-digit Diagnostic Trouble Code (DTC). The DTC is located in the left column of the DTC
table. If you have switched the printer on by pressing the "PRINT" button, the VAG1551 scan tool (ST) prints the message
identifying the malfunction and the DTC. Otherwise, DTCs are not displayed by the VAG1551 scan tool.
The contents of DTC memory remain stored until memory is erased, page 01
-15
.
Sporadically occurring malfunctions are identified via indication of "/SP" on the right-hand side of the display.
Static malfunctions that cannot be detected when the vehicle is stationary are also identified with "/SP" if the ignition has
been switched off and then on again.
The following DTC table includes all the DTCs that can be stored by the ABS control module -J104- and displayed and
printed out by the VAS5051 tester or VAG1551 scan tool. Malfunctions are listed by DTC number.
Pa
ge 42 of 66 Out
put Dia
gnostic Test Mode
(DTM
) (function 03
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.13

01-189

DTC
Possible cause
Corrective action
Printed output from
VAG1551 Scan Tool
(ST)

00283
Left front ABS wheel
speed sensor -G47-1)
Mechanical
malfunction
or:
Left rear ABS wheel speed sensor -
G47- installed incorrectly.
ABS wheel speed sensor rotor dirty or
damaged.
Excessive wheel bearing play.
ABS wheel speed sensor -G47-
malfunctioning.
Short circuit to Ground (GND). Repair Manual, Brake System, Repair Group 45

Repair Manual, Brake System, Repair Group 45
Repair Manual, Suspension, Wheels, Steering,
Repair Group 40
- Check installation of ABS wheel speed sensor.
- Check rotor, clean or replace- Replace wheel bearing- "Read measuring value block" display group 1
page 01
-140
.
- Carry out "Electrical test", step 5 page 01
-166
.
Left front ABS wheel
speed sensor -G47-
Open circuit/short
circuit to B+
Open circuit or short circuit to B+ in
wiring between ABS wheel speed
sensor -G47- and ABS control module -
J104-. - If nothing is displayed during "Read measuring value
block", and no malfunction could be determined in the
wiring or the ABS wheel speed sensor, replace the
hydraulic control unit.
Pa
ge 44 of 66 Out
put Dia
gnostic Test Mode
(DTM
) (function 03
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.13

01-190

DTC
Possible cause
Corrective action
Printed output from
VAG1551 Scan Tool
(ST)

00285
Right front ABS
wheel speed sensor
-G45-
1)
Mechanical
malfunction
or:
Left rear ABS wheel speed sensor -
G45- installed incorrectly.
ABS wheel speed sensor rotor dirty or
damaged.
Excessive wheel bearing play.
ABS wheel speed sensor -G45-
malfunctioning.
Short circuit to Ground (GND). Repair Manual, Brake System, Repair Group 45

Repair Manual, Brake System, Repair Group 45
Repair Manual, Suspension, Wheels, Steering,
Repair Group 40
- Check installation of ABS wheel speed sensor.
- Check rotor, clean or replace- Replace wheel bearing- "Read measuring value block" display group 1
page 01
-140
.
- Carry out "Electrical test", step 4 page 01
-166
.
Right front ABS
wheel speed sensor
-G45-
Open circuit/short
circuit to B+
Incorrect control module version.
Open circuit or short circuit to B+ in
wiring between ABS wheel speed
sensor -G45- and ABS control module -
J104-. - Check control module version page 01
-128
.
- If nothing is displayed during "Read measuring value
block", and no malfunction could be determined in the
wiring or the ABS wheel speed sensor, replace the
hydraulic control unit.
Pa
ge 46 of 66 Out
put Dia
gnostic Test Mode
(DTM
) (function 03
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.13

01-191

DTC
Possible cause
Corrective action
Printed output from
VAG1551 Scan Tool
(ST)

00287
Right rear ABS
wheel speed sensor
-G44-
1)
Mechanical
malfunction
or:
Left rear ABS wheel speed sensor -
G44- installed incorrectly.
ABS wheel speed sensor rotor dirty or
damaged.
Excessive wheel bearing play.
ABS wheel speed sensor -G44-
malfunctioning.
Short circuit to Ground (GND). Repair Manual, Brake System, Repair Group 45

Repair Manual, Brake System, Repair Group 45
Repair Manual, Suspension, Wheels, Steering,
Repair Group 42
- Check installation of ABS wheel speed sensor.
- Check rotor, clean or replace- Replace wheel bearing- "Read measuring value block" display group 1
page 01
-140
.
- Carry out "Electrical test", step 6 page 01
-166
.
Right rear ABS
wheel speed sensor
-G44-
Open circuit/short
circuit to B+
Incorrect control module version.
Open circuit or short circuit to B+ in
wiring between ABS wheel speed
sensor -G44- and ABS control module -
J104-. - Check control module version page 01
-128
.
- If nothing is displayed during "Read measuring value
block", and no malfunction could be determined in the
wiring or the ABS wheel speed sensor, replace the
hydraulic control unit.
Pa
ge 48 of 66 Out
put Dia
gnostic Test Mode
(DTM
) (function 03
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU02.01.13