Checking accelerator position sender G79 - vehicles with 6-cylinder engine — AUDI

Checking
accelerator position sender
G79
- vehicles with 6-cylinder engine
Special tools and workshop equipment required
Hand-held multimeter
V.A.G 1526C
Auxiliary measuring set
V.A.G 1594C
Adapter
V.A.G 1598/30
(engine code letters: AFB with manual gearbox or automatic gearbox: AKN with manual gearbox)
Adapter cable, 121-pin
V.A.G 1598/31
(engine code letters: AKE with manual gearbox or automatic gearbox: AKN with automatic gearbox)
Vehicle diagnostic, testing and information system
VAS 5051B
Procedure
Vehicle diagnostic, testing and information system
VAS 5051B
is connected; vehicle self-diagnosis and vehicle system
“01 - Engine electronics”
is selected. When doing this, the ignition must be switched on.
Display on
VAS 5051B
From the list
1
select diagnostic function
“08 - Read measured value block”
.
Display on
VAS 5051B
In zone
2
enter
2
for
“display group 002”
and confirm the entry by pressing the
Q
key.
1
Enter display group
Display on
VAS 5051B
Check values in zones
2
and
3
.
Display zones
Explanatory notes
2
… %
Accelerator pedal not depressed
Specification: 0.0 %
Press accelerator pedal down slowly
Specification:
Readout should increase steadily until it reaches 100 % (accelerator pedal fully depressed)
Vehicles with automatic gearbox: the kickdown switch pressure point must be distinctly felt before the full throttle stop position is reached.
3
…
Accelerator pedal not depressed
Specification: 0 1 0
Accelerator pedal depressed
Specification: 0 0 0
Press the
←
button to exit from the function
“08 - Read measured value block”
.
Press
“06 - End output”
.
Switch off ignition.
All models:
If the specifications for the initial and/or final readouts are not obtained:
Adjust
accelerator position sender
G79
Chapter
.
If the display does not change or only changes irregularly:
Checking internal resistance
Remove storage compartment on driver's side
Rep. Gr.
68
.
Unplug electrical connector on accelerator position sender
G79
in footwell on accelerator pedal.
Connect up multimeter for resistance measurement as follows.
Connector
Contact
Specification
1
+
3
Accelerator pedal not depressed
0.6 … 1.4 kΩ
2
+
3
Accelerator pedal not depressed
0.6 … 1.4 kΩ
4
+
6
Accelerator pedal not depressed
0.6 … 1.4 kΩ
Accelerator pedal depressed
∞ Ω
5
+
6
1)
Accelerator pedal not depressed
∞ Ω
Accelerator pedal fully depressed
0.6 … 1.4 kΩ
1)
Only vehicles with automatic gearbox.
If the specifications are not obtained:
Renew
accelerator position sender
G79
.
Checking wiring
Engine code letters: AFB with manual gearbox or automatic gearbox: AKN with manual gearbox:
Connect
adapter
V.A.G 1598/30
to connectors on wiring harness; do not connect engine control unit
Rep. Gr.
23
.
Engine code letters: AKN with automatic gearbox:
Connect
adapter cable, 121-pin
V.A.G 1598/31
to connectors of wiring harness; do not connect engine control unit. Connect earth clip of adapter cable to earth (not shown in illustration)
Rep. Gr.
23
.
All models:
Caution
To prevent damage to electronic components, select appropriate measuring range before connecting measuring leads and observe test requirements.
Check for open circuit and short to positive or earth in the following wiring:
Connector
Contact
V.A.G 1598/30
Socket
V.A.G 1598/31
Socket
1
4/08
69
2
4/09
12
3
4/07
50
4
4/13
70
5
1)
4/34
51
6
4/12
63
1)
Only vehicles with automatic gearbox.
Repair wiring connection if necessary.