brake AUDI A4 1999 B5 / 1.G Brakes Basic Setting 04 User Guide

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Test table: display group 6 Read measuring value
block 6
Indicated on display
0 volts to 18
volts
on
or
off
on
or
off 0 ...
131071


Workshop code:

The workshop code indicates the last workshop that executed the "Login Procedure" (function
11) under address word 03, "Brake electronics" page 01
-237
.
If no code is displayed, the "Login Procedure" under address word 03 "Brake Electronics" has
not been carried out yet.

Voltage at motor for ABS return flow pump:

off specified value, there is no voltage at the motor for the ABS return flow pump. on not permitted during "Read measuring value block", there is voltage at the motor for the ABS
return flow pump.
- Carry out "Electrical test", steps 12, 23 and 24.

ABS solenoid valve relay:

on specified value, relay was activated by ABS control module -J104- during ignition on. off not permitted during "Read measuring value block", the relay was not activated during "ignition on".
- Carry out "Electrical test", steps 11 and 22.
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Are you sure there are no electrical malfunctions
in the system? If you have made sure that there
are no electrical malfunctions in the system, you
will be able to identify any mechanical
malfunctions in the individual actuators if the
results of the output DTM are not as specified
here. Replace the relevant part.
With the Bosch 5.3 ABS/ESP the output
Diagnostic Test Mode (DTM) enables you to
check the electrically actuated hydraulic valves
and the pump motor in the hydraulic module. You
can also check that the brake lines going to the
four wheels are connected correctly.
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Notes:

The vehicle must be raised until all wheels are
free to turn. Ask a colleague to help. The
colleague will have to check the wheels to
determine whether they turn freely.
You can stop the test sequence at any time by
pressing the -C- button.
To avoid overloading the components being
checked, they are actuated during the test
sequence for a period of 60 (or 90) seconds.
The actuator test will be terminated if the "
button" is not pressed within this period.

The ABS warning light and the red "brake
system malfunction" symbol blink during the
test.
Pressing the brake pedal repeatedly this
relieves the vacuum in the brake booster. For
this reason, the brake pedal must be pressed
harder in order to achieve the same braking
effect. Your work will be easier if you run the
engine briefly. This will build up vacuum in the
brake booster again.
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- Connect VAS5051 tester or VAG1551 scan tool
and select the address word 03 "Brake
Electronics".

- Check the control module version page 01
-
128
and press the button.
Rapid data transfer
HELP
Select function XX

Indicated on display:
- Press buttons -0- and -3- to select "Output Diagnostic Test Mode
(DTM)" function 03.
Rapid data transfer
Q
03 - Output Dia
gnostic Test Mode
(DTM
)

Indicated on display:
- Press -Q- button to confirm input.
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Output Diagnostic Test Mode (DTM)
-
ABS hydraulic pump -
V64-

Indicated on display:
ABS hydraulic pump -V64- must start running. This is audible.

When you put your foot on the brake pedal you can feel it vibrating. The
brake pedal vibrates because the hydraulic pump generates pressure
pulses in the brake lines. The pressure pulses generate oscillations.
These are directed to the brake pedal and make it vibrate.
The pressure pulses in the brake lines are not sufficient to lock the
wheels.
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Output Diagnostic Test Mode (DTM)
-
Operate brake

Indicated on display:
-
Press button.
Output Diagnostic Test Mode (DTM)
-
Ifl: 0V
Ofl: 0V
fl wheel locked

Indicated on display:

When you press the brake pedal, brake fluid pressure will be built up in all
four calipers. All four wheels lock.
Requirement for this: mechanical/hydraulic components of the brake
system must be fully functional. This means that the master brake cylinder
is able to build up pressure in all wheel cylinders and the hydraulic
connections and lines are all sealed properly.
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If the wheels do not lock, visually inspect brake fluid reservoir, master
brake cylinder, hydraulic unit, and calipers.
Concentrate on the left-front wheel first. The function of the control
elements for this wheel is tested first.
Note:
This test step in the output diagnostic test mode corresponds to the
"pressure build-up" phase during ABS-controlled braking.
-
Press button.
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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.
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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.
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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 unit.
Note:
This test step in the output diagnostic test mode corresponds to the
"pressure reduction" phase during ABS-controlled braking.
-
Press button.
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