check engine AUDI A4 1995 B5 / 1.G ATQ Engine Tank Ventilation Checking Workshop Manual
Page 2 of 7
24-129
Note:
The Evaporative Emission (EVAP) canister purge
regulator valve is also called the Tank Ventilation
Valve (TVV) and is sometimes referred to as the
EVAP valve.
Checking for proper seal
Solenoid valve is closed when no voltage is
present.
- Disconnect hoses from EVAP valve; harness
connector remains connected.
- Attach assisting hose to one connection of
EVAP valve.
- 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.
- Initiate output DTM and activate Evaporative
Emission (EVAP) canister purge regulator valve
-N80- Page 01
-56
.
Output Diagnostic Test Mode
Indicated on display:
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Page 5 of 7
24-131
Checking voltage supply
Test requirements:
Fuse for the EVAP valve OK.
Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder
Fuel Pump (FP) OK, checking Page 24
-
49
.
Note:
Voltage is supplied to the EVAP valve via the
Fuel Pump (FP) relay.
- Disconnect connector at EVAP valve.
- Connect VAG1527B voltage tester as follows:Harness connector
Terminal
Measure to
1 Engine Ground (GND)
- Operate starter briefly (engine can also start).
LED must light up.
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Page 7 of 7
24-133
If LED does not blink or if it remains constantly
lit:
- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24
-17
.
If wire connection is OK: - 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 64
- Repair open circuit or short circuit if necessary.
- Replace Engine Control Module (ECM) Page 24
-21
.
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