battery AUDI A4 2000 B5 / 1.G ATQ Engine Oxygen Sensor Control Checking
Page 57 of 63
24-122
- Start engine.
Specification: approx. battery voltage,
possibly fluctuating
Notes:
At certain operating points, the ECM "pulses"
the Ground (GND) for oxygen sensor heating.
This means that the Ground (GND) is
constantly switched on and off at these points.
It is therefore possible that the voltage
displayed on the tester will fluctuate.
It is possible to observe the ECM switching
oxygen sensor heating on and off within the
function "read measuring value block", display
group numbers 041 and 042.
If there is no voltage:
- Connect multimeter for voltage measurement as follows:Harness connector
Terminal
Measure to
1 (B+) Vehicle Ground (GND)
- Operate starter briefly.
Pa
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.FU05.24.3
Page 58 of 63
Specification: approx. battery voltage
Pa
ge 58 of 63 Ox
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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Page 59 of 63
24-123
If there is no voltage again:
- Check wire connection from terminal 1 to Fuel
Pump (FP) relay via fuse for open circuit.
Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder If voltage supply is OK:
If there is no voltage: - Connect multimeter for voltage measurement as follows:Harness connector
Terminal
Measure
to
2 (Ground -GND- activation of Engine Control Module -
ECM-) B+
- Start engine.
Specification: approx. battery voltage, possibly fluctuating
- Switch ignition off.
- Connect VAG1598/31 test box at wiring harness to ECM, do not
connect ECM Page 24
-17
.
Pa
ge 59 of 63 Ox
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en sensor control, checkin
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.FU05.24.3