1995 AUDI A4 APB Engine Electronic Engine Power Control Checking Workshop Manual

The Abbreviation "ADP" stands for adaptation.
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Note:
If the adaptation process is interrupted by the
control unit, the cause could be one of the
following:

The throttle valve is unable to close completely
(e.g. because of dirt).
The harness connectors (e.g.: at throttle valve
control module) are loose, not properly
connected or the contacts at the connector are
corroded or bent.
Battery voltage too low.
Throttle valve control module or wiring is
faulty.
The engine was started or the accelerator pedal
was depressed during the adaptation process.
Distortion of throttle valve housing (check bolts:
10 Nm)
When the adaptation process is interrupted the
message "Function is unknown or cannot be
carried out at the moment" will appear on the
fault reader display. The adaptation process will
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start again automatically the next time the
ignition is switched on (for several seconds).

-
End engine basic setting by pressing the
button.

- Press buttons -0- and -6- to select "End Output"
function and confirm input with -Q- button.
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Angle sensor -1- for throttle drive
(power accelerator actuation) -G187-
and angle sensor -2- for throttle drive
(power accelerator actuation) -G188,
checking

The angle sensor -1- for throttle drive (power
accelerator actuation) -G187 and angle sensor -
2- for throttle drive (power accelerator actuation)
-G188 inform the engine control module of the
position of the throttle valve. Both angle sensors
are located in the throttle valve control module.

- 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.
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 Measurin
g 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.
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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.
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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
.
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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.
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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
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