1997 AUDI A4 Brakes Output DTM 03 Workshop Manual

01-156

-
Press button.Output Diagnostic Test Mode (DTM)
-
Ifl: B+
Ofl: 0V
fl wheel locked

Indicated on display:
Keep pressing brake pedal.

Inlet valve is activated. It interrupts the brake line. However, fluid pressure
is still maintained in the wheel cylinder. The left-front wheel remains
locked.
Note:
This test step in the output diagnostic test mode corresponds to the
"maintain pressure" phase during ABS-controlled braking.
-
Press button.
Pa
ge 9 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

01-157

Output Diagnostic Test Mode (DTM)
-
Ifl: B+
Ofl: B+
fl wheel free

Indicated on display:
Keep pressing brake pedal.
The inlet valve and the outlet valve for the left-front wheel are activated.
The hydraulic pump starts running and reduces the fluid pressure in the
caliper via the open outlet valve.

The brake pedal must not give, and should press harder against your
foot.
You should now be able to turn the left-front wheel.
If you cannot turn the wheel, check whether the brake line for the left-front
wheels is connected correctly. If yes, this indicates a mechanical
malfunction in one of the valves, providing there is no electrical
malfunction in the system. Replace hydraulic control unit.
If the pedal gives under your foot, this means that the inlet valve or the
check valve activated in parallel to the inlet valve is leaking. Replace
hydraulic control unit.
Note:
This test step in the output diagnostic test mode corresponds to the
"pressure reduction" phase during ABS-controlled braking.
-
Press button.
Pa
ge 10 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

01-158

Output Diagnostic Test Mode (DTM)
-
Ifl: B+
Ofl: 0V
fl wheel free

Indicated on display:
ABS/EDL hydraulic pump -V64- will stop running.

Keep pressing brake pedal. Only the inlet valve is still activated and
interrupts the brake line. If the inlet valve is not leaking, you should be
able to turn the left-front wheel.
If you cannot turn the wheel, this means that the inlet valve or the check
valve activated in parallel to the inlet valve is leaking. Replace hydraulic
control unit.
-
Press button.
Pa
ge 11 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

01-159

Output Diagnostic Test Mode (DTM)
-
Ifl: 0V
Ofl: 0V
fl wheel locked

Indicated on display:

Keep pressing brake pedal. Inlet valve is no longer being activated. It is
no longer interrupting the brake line. The brake pedal will give perceptibly
under your foot. Fluid pressure is built again in the left-front caliper. The
wheel will be locked.
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Release brake

Indicated on display:
-
Press button.
Pa
ge 12 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

01-160

Continue output Diagnostic Test Mode (DTM)
in order to check the front right, rear left, and
rear right wheels in sequence. The test steps
indicate the procedure for the front left wheel.
They will therefore not be repeated in detail. Output Diagnostic Test Mode (DTM)
-
Operate brake

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Ifr: 0V
Ofr: 0V
fr wheel locked

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Ifr: B+
Ofr: 0V
fr wheel locked

Indicated on display:
ABS/EDL hydraulic pump -V64- must start running.
The brake pedal must not give. -
Press button.
Output Diagnostic Test Mode (DTM)
-
Ifr: B+
Ofr: B+
fr wheel free

Indicated on display:
ABS/EDL hydraulic pump -V64- will stop running. -
Press button.
Pa
ge 13 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

01-161

Output Diagnostic Test Mode (DTM)
-
Ifr: B+
Ofr: 0V
fr wheel free

Indicated on display:
Brake pedal must give noticeably. -
Press button.
Output Diagnostic Test Mode (DTM)
-
Ifr: 0V
Ofr: 0V
fr wheel locked

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Release brake

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Operate brake

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Irl 0V
Orl: 0V
rl wheel locked

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Irl B+
Orl: 0V
rl wheel locked

Indicated on display:
ABS/EDL hydraulic pump -V64- must start running.
The brake pedal must not give. -
Press button.
Pa
ge 14 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

01-162

Output Diagnostic Test Mode (DTM)
-
Irl B+
Orl: B+
rl wheel free

Indicated on display:
ABS hydraulic pump -V64- will stop running. -
Press button.
Output Diagnostic Test Mode (DTM)
-
Irl B+
Orl: 0V
rl wheel free

Indicated on display:
Brake pedal must give noticeably. -
Press button.
Output Diagnostic Test Mode (DTM)
-
Irl 0V
Orl: 0V
rl wheel locked

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Release brake

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Operate brake

Indicated on display:
-
Press button.
Pa
ge 15 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

01-163

Output Diagnostic Test Mode (DTM)
-
Irr: 0V
Orr: 0V
rr wheel locked

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Irr: B+
Orr: 0V
rr wheel locked

Indicated on display:
ABS/EDL hydraulic pump -V64- must start running.
The brake pedal must not give. -
Press button.
Output Diagnostic Test Mode (DTM)
-
Irr: B+
Orr: B+
rr wheel free

Indicated on display:
ABS/EDL hydraulic pump -V64- will stop running. -
Press button.
Output Diagnostic Test Mode (DTM)
-
Irr: B+
Orr: 0V
rr wheel free

Indicated on display:
Brake pedal must give noticeably. -
Press button.
Output Diagnostic Test Mode (DTM)
-
Irr: 0V
Orr: 0V
rr wheel locked

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Release brake

Indicated on display:
Pa
ge 16 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