brake sensor AUDI A4 1997 B5 / 1.G Brakes Basic Setting 04 Workshop Manual

01-250

ESP driving and system test

The ESP driving test is used to test the
plausibility of the signals from the sensor for
transverse acceleration, yaw sensor, and
pressure sensor.

Road test vehicle
Some DTCs are only recognized by the On
Board Diagnostic (OBD)while the vehicle is
moving. You can check the entire system during
a road test. During road test, drive at a speed of
at least 60 km/h for 30 seconds. Check traffic
conditions and perform an ABS regulated braking
when appropriate. You will feel a pulsing in the
brake pedal indicating the system is active.

Note:
Once the ESP driving test has been initiated, it
cannot be aborted and must be performed
completely. After exiting the diagnostic, the
ABS/EDL and ASR/ESP lamps remain switched
on in order to indicate that the test is active and
that system function is not available yet.
Warning, ABS and ESP not functioning!
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01-256

Read Measuring Value Block (function
08)

The control module can transmit measured
values to the VAS5051 tester and VAG1551
Scan Tool (ST). These measured values provide
information about the operational status of the
system and the sensors connected to it. In many
cases the data supplied can be used to
troubleshoot and repair malfunctions. The
measured values provided by ESP are contained
in six display groups, which can be accessed via
their display group numbers.

- Connect the VAS5051 tester or VAG1551 Scan
Tool (ST) and select the address word 03 "Brake
Electronics".
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01-258
Test table: display group 1
Notes:

Display fields 1 through 4 show the current wheel circumference speeds in km/h. These are calculated by the ABS control
module -J104- on the basis of the signals received from the wheel speed sensors. If one of the display fields shows no
reading, proceed as for DTCs 00283, 00285, 00287, 00290 "ABS Wheel Speed Sensor" DTC table page 01
-357
.
In order to check whether wheel speed sensors are properly allocated to each wheel, the vehicle must be raised. On
vehicles with manual transmission put the gear shift lever in neutral. On vehicles with automatic transmission move the
selector lever to position "N". Turn appropriate wheel by hand. Remaining drive wheels must be secured against turning.
When a vehicle is accelerated uniformly on a dry surface, the displayed value will increase continuously by whole
numbers; e.g. 6 km/h, 7 km/h, 8 km/h ... . The difference between displayed values 1-4 should not be more than 1 km/h
(error from out-of-round wheels). If the values jump, for instance from ...6km/h, 7 km/h, to 12 km/h...or if the difference
between the displayed values is greater than 1 km/h, then check the installation of the wheel speed sensors and rotors. Repair Manual, Brake System, Repair Group 45

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01-270
Test table: display group 5 Read measuring value
block 5
Indicated on display
- 720
...
+720
- 69
/s ...
+ 69 /s
- 41
bar ...
+292
bar - 25 m/s2 ...
+ 25 m/s2


Transverse acceleration:

Specification with vehicle at standstill: 0....0.7 m/s2 Specification with steering wheel fully turned at a speed of 20 km/h: max. 6.0 m/s2; the
value of the measured value increases steadily. Another test for the sensor is located page 01
-271
; Fig. 1
.

Brake pressure:

Specification with brake pedal not depressed: 0....5 bar

Rotation rate:
Specification with vehicle at standstill: 3 /sSpecification with steering wheel fully turned at a vehicle speed of 20 km/h: max. 65 /s; the value of the
measured value increases steadily.
Steering angle:

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