AUDI A8 1995 D2 / 1.G ATQ Engine Additional Signals Testing Owner's Manual

24-181
If specified values are not obtained:

- Check adjustment of switch or

- Replace brake light switch / brake pedal
switch.
If specified values are obtained:

Checking voltage supply

- Connect VAG1527B voltage tester as follows:Harness connector
Terminal
Measure to
1 Chassis Ground (GND)

LED must light up.
- Switch ignition on.
Harness connector
Terminal
Measure to
3 Chassis Ground (GND)

LED must light up.
Pa
ge 21 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

24-182
If LED does not light up:

- Check wire connection from terminal 1 or 3 of
connector for open circuit and short circuit to
Ground (GND):

Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder
- Repair open circuit or short circuit if
necessary.
If LED lights up:

Checking activation

- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24
-17
.

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

Harness connector
Terminal
VAG1598/31 test box
Socket
2 56
4 55
Pa
ge 22 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

- Repair open circuit or short circuit if
necessary.
Pa
ge 23 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

24-183

Clutch vacuum vent valve switch -F36-,
checking


Note:
This signal helps prevent excessive RPM
oscillations and tip-in shocks when clutch is
disengaged and is required for the cruise control
system.

Test sequence

- Connect VAS5051 tester or VAG1551 scan tool
and select the control module for engine
electronics using "address word" 01 Page 01
-
9 .

Ignition must remain switched on for this.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
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -6- and -6- to select "display group number 066" and
press -Q- button to confirm input.
Read Measuring Value Block 66

Indicated on display:
Pa
ge 24 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

1
2
3
4
- Check Clutch Pedal Position (CPP) switch in display field 2.
Pa
ge 25 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

24-184


Display fields

1 2 3 4
Display group 066: Signals to Engine Control Module (ECM)
Display xxx km/h
XXXX xxx km/h XXXX
Indicated ACTUAL speed
Switch positions SPECIFIED speed Switch positions
Functional range
X0XX
X1XX
Specified value
X0XX
(at clutch pedal
not operated)

X1XX
(at clutch pedal
operated)
Notes
Value:
X = no significance
Pa
ge 26 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

24-185
If indications do not resemble description:

Check switch

- Remove driver-side storage compartment.

Repair Manual, Body
-Interior, Repair Group
68; Instrument Panel; Removing Driver
-Side
Storage Compartment


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

Note:
Connector sockets are marked on the back side
of the connector.

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


Specification: approx. 0

- Depress clutch pedal.


Specification: (no continuity)
Pa
ge 27 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

If specified value is not obtained:

- Check adjustment of switch or

- Replace Clutch Pedal Position (CPP) switch.
Pa
ge 28 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

24-186
If specified value is obtained:

Checking voltage supply

If LED does not light up:
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder - Connect VAG1527B voltage tester as follows:Harness connector
Terminal
Measure to
1 Chassis Ground (GND)
- Switch ignition on.

LED must light up.
- Check wire connection from terminal 1 of connector to fuse for open
circuit and short circuit to Ground (GND):
Pa
ge 29 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6

24-187
If LED lights up:

Checking activation

- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24
-17
.

- Check the following wire connection for open circuit and short circuit to
Ground (GND) and B+: Harness connector
Terminal
VAG1598/31 test box
Socket
2 39
- Repair open circuit or short circuit if necessary.
Pa
ge 30 of 44 Additional si
gnals, testin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.6