1997 AUDI A4 APB Engine Electronic Engine Power Control Checking Workshop Manual

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.
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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.
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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.
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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.
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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 %).
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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
.
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24-163

Checking voltage supply of accelerator
position sensors

- Remove storage compartment on driver's
side.

Repair Manual, Body Interior, Repair Group
68


- Disconnect harness connector for accelerator
position sensor.

- Switch ignition on.

- Connect hand-held multimeter (voltage range) between the following
sockets on the connector: 6-pin connector on wiring harness, socket
Specification
2 + Ground (GND) approx. 5 V
1 + 3 approx. 5 V
5 + Ground (GND) approx. 5 V
5 + 4 approx. 5 V
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24-164
If the specifications are obtained:

- Check signal wiring Page 24
-164
.
If the specifications are not obtained:

- Check wiring between Engine Control Module
(ECM) and accelerator position sensors.

Checking wiring

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

- Check for open circuit and short to B+ or Ground
(GND) in the following wiring connections:

Connector socket
VAG1598/31 test box
Socket
1 72
2 73
3 36
4 35
5 33
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pair&id=AUDI.B5.FU04.24.4