1995 AUDI A4 driver

24-113


Electronic Engine Power
Control (EPC) (E-Gas),
checking

E-Gas system, function

For E-Gas, the throttle valve is not operated by a
cable from the accelerator pedal. There is no
mechanical connection between the accelerator
pedal and the throttle valve.
The position of the accelerator pedal is
communicated to the Engine Control Module
(ECM) via two sensors for accelerator pedal
position (variable resistances; stored in one
housing) that are connected with the accelerator
pedal.
The accelerator pedal position (driver's intention)
is a main input unit for the ECM.
Operation of the throttle valve occurs via an
electric motor (throttle valve actuator) in the
throttle valve control module. This is true across
the entire engine speed and engine load
spectrum.
The throttle valve is operated by the throttle valve
actuator according to the instructions of the
ECM.
With ignition switched on and engine off, the
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) (E-Gas
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pair&id=AUDI.B5.FU06.24.4

24-134
Both the Throttle Position (TP) sensor -G79- and
the Sender -2- for accelerator pedal position -
G185- are located at the accelerator pedal and
communicate the driver's intentions to the ECM
completely independently of each other. Both
sensors are stored in one housing.

Test sequence

- Connect VAS5051 tester or VAG1551 scan tool
and select control module for engine electronics
using "address word" 01 Page 01
-10
. Ignition
must remain switched on.
Rapid data transfer
HELP
Select function XX

When indicated on display
- Press buttons -0- and -8- to select "Read Measuring Value Block" and
press -Q- button to confirm input.
Read measurin
g value block
Q
Enter display group number XXX

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

Indicated on display
- Check specified values for E-gas potentiometer voltages in display
fields 3 and 4.
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) (E-Gas
), checkin
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pair&id=AUDI.B5.FU06.24.4

24-137

Checking voltage supply of Throttle Position
(TP) sensor

- Remove driver-side storage compartment.

Repair Manual, Body Interior, Repair Group
68; Instrument panel; Driver
-side storage
compartment, removing


- Disconnect harness connector for accelerator
pedal position sensor.

- Switch ignition on.

If specified values are obtained: - Connect multimeter for voltage measurement as follows:Harness connector
Terminal
Specified value
1 + Ground (GND) about 5 V
1 + 5 about 5 V
2 + Ground (GND) about 5 V
2 + 3 about 5 V
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ge 30 of 51 Electronic En
gine Power Control
(EPC
) (E-Gas
), checkin
g
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p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU06.24.4

24-146
If indications do not resemble description:

Check switch

- Remove driver-side storage compartment.

Repair Manual, Body Interior, Repair Group
68; Instrument panel; Driver
-side storage
compartment, removing


- Disconnect harness connector at brake light
switch and brake pedal switch.

If specified values are not obtained: - Connect multimeter between terminal 1 and 2 for resistance
measurement.

Specification: (no continuity)
- Depress accelerator pedal.

Specification: approx. 0
- Connect multimeter between terminal 3 and 4 for resistance
measurement.

Specification: approx. 0
- Depress accelerator pedal.

Specification: (no continuity)
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ge 41 of 51 Electronic En
gine Power Control
(EPC
) (E-Gas
), checkin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU06.24.4

24-152
If indications do not resemble description:

Check switch

- Remove driver-side storage compartment.

Repair Manual, Body Interior, Repair Group
68; Instrument panel; Driver
-side storage
compartment, removing


- Disconnect harness connector at Clutch Pedal
Position (CPP) switch.

- Connect multimeter between terminal 1 and 2
for resistance measurement.


Specification: approx. 0

- Depress clutch pedal.


Specification: (no continuity)
If specified value is not obtained:

- Replace Clutch Pedal Position (CPP) switch.
If specified value is obtained:
Pa
ge 48 of 51 Electronic En
gine Power Control
(EPC
) (E-Gas
), checkin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU06.24.4