ignition AUDI A4 1999 B5 / 1.G Brakes ESP Bosch 5.3 Workshop Manual

01-218

ESP system sensors and components,
description


Control module for ABS with EDL/ASR/ESP -
J104-
The control module is combined with the
hydraulic unit as one unit. It controls the ESP,
ABS, EDL, ASR, EBD and ETR (Engine Torque
Reduction) functions. When ignition is switched
on, the control module performs a self-test. All
electrical connections are monitored constantly
and the solenoid valves are periodically checked
for function. If the control module fails entirely,
only the normal brake system will be available.

Steering angle sensor -G85-
The steering angle sensor is housed together
with the airbag spiral spring/return spring with
slip ring. It is located on the steering column
between the steering column switch and steering
wheel. It transmits the steering wheel's steering
angle to the ABS control module -J104 for
ABS/ASR/ESP via the CAN-bus. After replacing
the control module or the sensor, a zeroing must
be performed. For malfunctioning sensor, the
ESP function is not available.
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01-222

Warning light functions, overview


If On Board Diagnostic (OBD) has detected a
malfunction in the system, it indicates the
malfunction by lighting up warning lamps when
ignition is switched on. The warning lamps are
located in the instrument cluster.

Instrument cluster without DIS
The illustration shows the ABS/EDL warning light -K47- (right arrow),
the warning light for brake system -K118- (center arrow, red symbol
for "brake system malfunction") and the traction control indicator light -
K86- (left arrow).

Instrument cluster with DIS
Repair manual, Brake System, Repair Group 46

For DIS, there is no warning light for brake system -K118-. The red
"brake system malfunction" symbol appears in the display. If the ABS/EDL warning light -K47 and the red symbol for "Brake
system malfunction" are not lit, but the brake system is not functioning
properly, check for malfunctions in the mechanical/hydraulic brake
system components.
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01-223

"Brake
malfunction"
symbol ABS/EDL
warning light
-K47- Traction control
indicator light
-K86- Possible reasons why the indicator lamps light up
off off off
All indicator lights go out after the self-test (approximately three
seconds after the ignition is switched on). All systems are OK.
Pay attention to the notes on the next page
off off blinking ASR/ESP is in adjustment mode. The ASR/ESP indicator light
blinks approximately 3 times per second.
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01-224

"Brake
malfunction"
symbol ABS/EDL
warning
light
-K47- Traction
control
indicator
light
-K86- Possible reasons why the indicator lamps light up
off on on
A self-test is performed after the ignition is switched on. If all systems
are OK, warning lights, the ABS warning light -K47- and traction
control indicator light -K86- go out after approximately three seconds.
If the indicator lamps do not light up, check the relevant lamps carry
out "Electrical Test", steps 17 and 19. The possible causes are as
follows:

Electrical Wiring Diagrams, Troubleshooting & Component Locations
Repair Manual, Electrical Equipment, Repair Group 90.



The battery voltage is insufficient. None of the lamps in the instrument
cluster light up. Check the battery. The ABS warning light -K47- does not light up during the self-test. There
is a short to Ground (GND) in the wiring that controls the ABS/EDL
warning light between terminal 32 of the ABS control module -J104- and
the instrument cluster. This malfunction does NOT influence the control
of the traction control indicator light.
Pa
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01-228

"Brake
malfunction"
symbol ABS/EDL
warning
light
-K47- Traction
control
indicator
light
-K86- Possible reasons why the indicator lamps light up
on on on The ABS and traction control indicator lights go on, and three seconds after
the ignition is switched on the red "brake system malfunction" symbol goes
on.
WARNING!
The brake system is only partially functional. Because brake pressure at
the rear wheels is no longer regulated vie Electronic Brake Distribution
(EBD), the rear wheels can lock even during light braking (excessive
braking at rear axle). This can cause the rear of the vehicle to break
loose and thereby cause and accident.
Note: For vehicles with automatic transmission, the red "brake system
malfunction" symbol does not appear immediately after the ignition is
switched on. Instead, the note "Depress brake pedal before engaging gear"
appears in the display. Press the brake pedal and select a gear. The red
brake warning light appears, if the light control is working properly.
A malfunction deactivated the ABS/EDL, ASR/ESP and the "Electronic
Brake Distribution" (EBD).Check DTC memory page 01
-356
. Pa
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01-229

"Brake
malfunction"
symbol ABS/EDL
warning
light
-K47- Traction
control
indicator light
-K86- Possible reasons why the indicator lamps light up
off off on
The traction control indicator light does not turn off after the self-
test.


There is a malfunction that only affects the traction control. The
ABS/EDL and EBD systems are not deactivated. Check DTC
memory page 01
-356
.
Traction control has been switched off using the traction control
button. If the traction control indicator light does not light up in this
case, check the switch and the indicator light, carry out the
"Electrical test", steps 19 and 20. Short circuit to B+ in the ASR/ESP button: The traction control
indicator light goes out five minutes after the ignition is switched on.
Carry out "electrical test", step 20. There is a short to Ground (GND) in the wiring that controls the
traction control indicator light between terminal 31 of the ABS
control module -J104- and the instrument cluster. Carry out
"electrical test", step 19.
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01-230

"Brake
malfunction"
symbol ABS/EDL
warning
light
-K47- Traction
control
indicator light
-K86- Possible reasons why the indicator lamps light up
on on off
No DTCs are stored in DTC memory. The ABS and traction control
warning lights do not go out after the self-test, and three seconds
after the ignition is switched on the red "brake system malfunction"
symbol goes on. There is an open circuit or short circuit to B+ in the wiring that
controls the traction control indicator light between terminal 32 of
the ABS control module -J104- and the instrument cluster; carry
out "Electrical test" step 17. Voltage supply for control module less than 7 volts; carry out
"Electrical test" step 21.
on off off
No DTCs are stored in DTC memory. The red "brake system
malfunction" symbol remains lit after the ignition is switched on.
The brake fluid level is too lowMalfunction in instrument cluster: Carry out "Electrical test", step
18.
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