instrument cluster AUDI A4 1998 B5 / 1.G ATQ Engine Additional Signals Testing Workshop Manual
Page 2 of 44
24-166
Engine speed signal, checking
Note:
The engine speed signal is output at terminal 37
of the Engine Control Module (ECM). The signal
is used, among other things, for RPM display in
the instrument cluster.
- 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+:
Test box
VAG1598/31
Socket
Instrument cluster
Terminal
37 Electrical Wiring Diagrams,
Troubleshooting & Component
Locations binder
- Repair open circuit or short circuit if
necessary.
Pa
ge 2 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
Page 4 of 44
24-168
Vehicle speed signal, checking
Notes:
The vehicle speed signal is generated by the
Vehicle Speed Sensor (VSS) -G68- (at
transmission) and processed in the instrument
cluster.
The processed signal enters at terminal 54 of
the ECM and is used for idle stabilization and
tip-in shock reduction during shifting.
Test requirement:
Function and display of speedometer OK.
Troubleshooting:
Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder
Pa
ge 4 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
Page 6 of 44
24-170
- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24
-17
.
- Connect VAG1527B voltage tester to sockets 3
(B+) and 54 (VSS) of VAG1598/31 test box.
- Switch ignition on and turn front left wheel by
hand.
LED must blink (very brief blink signal).
If LED does not blink:
- Check the following wire connection for open
circuit and short circuit to Ground (GND) and B+:
Test box
VAG1598/31
Socket
Instrument cluster
Terminal
54 Electrical Wiring Diagrams,
Troubleshooting & Component
Locations binder
- Repair open circuit or short circuit if
necessary.
Pa
ge 6 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
Page 7 of 44
24-171
Wire for fuel level signal, checking
Notes:
The Engine Control Module (ECM) receives the
fuel level signal from the instrument cluster.
The processed signal enters at terminal 30 of
the ECM and is used to determine the cause of
certain recognized malfunctions (e.g.
combustion misfires).
- 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+:
Test box
VAG1598/31
Socket
Instrument cluster
Terminal
30 Electrical Wiring Diagrams,
Troubleshooting & Component
Locations binder
- Repair open circuit or short circuit if
necessary.
Pa
ge 7 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