AUDI A4 1996 B5 / 1.G APB Engine Electronic Engine Power Control Checking Owner's Manual

24-154
Note:
The engine control module converts the voltage readings from the angle sensors into percentages of 5 V and displays them as percentages. (A signal wire voltage of 5 V is equivalent to 100%.) Read Measuring Value Block 62
1
2
3
4

Indicated on display
- Check specified display values for electronic throttle potentiometer
voltages.

Display fields

1 2 3 4
Display Group 062: Electronic throttle potentiometer voltages
Display
xx %
xx % xx % xx %
Indicates
Throttle valve angle
(angle sensor 1) Throttle valve angle
(angle sensor 2) Accelerator position
sensor 1 Accelerator position
sensor 2
Work Range
min.: 0 %
max.: 100 % min.: 0 %
max.: 100 % min.: 0 %
max.: 100 % min.: 0 %
max.: 100 %
Specified value
3 - 93 %
(Idle value: 8 - 18%) 97 - 3 %
(Idle value: 80 - 90%) 12 - 97 % 4 - 49 % - Observe display fields 1 and 2.
- Slowly depress accelerator pedal to full throttle position.
Pa
ge 21 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

24-155
The percentage value in display field 1 should
rise steadily, but without covering the full
tolerance range between 3 - 93 %.
The percentage value in display field 2 should
also rise steadily but without covering the full
range of values (in this case 4 - 49 %).
If the display values do not appear as described:

- Check voltage supply and wiring to accelerator
position senders Page 24
-163
.
Observe harness connectors for the following:
Loose connectors, not properly engaged or
corroded.

Electrical Wiring Diagrams, Troubleshooting &
Component Locations
- Check accelerator position sensors Page 24
-
159
.
Pa
ge 22 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

24-156

Notes:

The reason why the value in display field 1 rises
and the value in display field 2 falls is because
the potentiometers (angle senders) in the
throttle valve control module work in opposite
directions.
The percentage value for the first potentiometer
increases as the voltage rises towards 5 V
because the voltage at this potentiometer
increases as the throttle valve opens.
The percentage value for the second
potentiometer decreases as the voltage drops
away from 5 V and towards 0 V because the
voltage at this potentiometer decreases as the
throttle valve opens.
Pa
ge 23 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

24-157

Checking voltage supply to throttle valve
control module

- Disconnect harness connector from throttle
valve control module.

- Switch ignition on.

If the specifications are not obtained, test wiring connections from engine
control module to throttle valve control module Page 24
-158
.
If the readouts match the specifications, test also the signal wires and
activation wires for the throttle valve positioner Page 24
-158
. - Connect hand-held multimeter (voltage range) between the following
sockets on connector:
6-pin connector on wiring harness, socket
Specification
2 + Ground (GND) approx. 5 V
2 + 6 approx. 5 V
Pa
ge 24 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

24-158

Checking wiring for voltage, signal and
activation

- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.

Test the following wiring connections for open circuits and short to B+ or
Ground (GND).
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If no wiring malfunction is detected:
6-pin connector on wiring harness,
socket
VAG1598/31 test box,
socket
1 92
2 83
3 117
4 84
5 118
6 91
Resistance in wiring: max. 1.5 ohm
- Repair any open/short circuit as necessary.- Replace throttle valve control module.
Pa
ge 25 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

24-159

Throttle Position (TP) sensor -G79 and
Sender -2- for accelerator pedal position
-G185, checking


Component location of Throttle Position (TP) sensor -G79 and
Sender -2- accelerator pedal position
The Throttle Position (TP) Sensor -G79 and Sender -2- for accelerator
pedal position -G185 are located at the accelerator pedal. Both sensors
inform (completely independently of the other) the engine control module
of the driver's throttle requirement (pedal position). Both sensors are
located in a single housing.
- Connect vehicle diagnostic, testing and information system VAS 5051
or VAG1551 scan tool and select engine electronics control module by
entering address word "01" Page 01
-9 . When doing this the ignition
must be switched on.
Pa
ge 26 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

24-160

Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -8- to select function "Read Measuring Value
Block" and confirm entry with -Q- button.
Read Measuring Value Block
Q
Input displa
y group number
XXX

Indicated on display
- Press buttons -0-, -6- and -2- to select "display group number 062" and
confirm entry with -Q- button.
Read Measuring Value Block 62
1
2
3
4

Indicated on display
- Observe specification for electronic throttle potentiometer voltages.
Pa
ge 27 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

24-161


Display fields

1 2 3 4
Display Group 062: Electronic throttle potentiometer voltages
Display xx % xx %
xx %
xx %
Indicates Throttle valve angle
(angle sensor 1) Throttle valve angle
(angle sensor 2) Accelerator position
sensor 1 Accelerator position
sensor 2
Work Range min.: 0 %
max.: 100 % min.: 0 %
max.: 100 % min.: 0 %
max.: 100 % min.: 0 %
max.: 100 %
Specified value 3 - 93 % 97 - 3 %
12 - 97 %
(Idle value: 12 - 18%) 4 - 49 %
(Idle value: 4 - 13%)
Note:
The engine control module converts the voltage
readings from the angle sensors into
percentages of 5 V and displays them as
percentages. (A signal wire voltage of 5 V is
equivalent to 100%.)

- Observe display fields 3 and 4.

- Slowly depress accelerator pedal to full throttle
position.
Pa
ge 28 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

The percentage value in display field 3 should
rise steadily, but without covering the full
tolerance range between 3 - 93 %.
The percentage value in display field 4 should
also rise steadily but without covering the full
range of values (in this case 4 - 49 %).
Pa
ge 29 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4

24-162

Note:
The value shown in display field 3 should always
be about the double of the value shown in
display field 4.
If the display values do not appear as described:

- Check voltage supply and wiring to accelerator
position sensors Page 24
-163
.
Pa
ge 30 of 39 Electronic En
gine Power Control
(EPC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.4