light AUDI A4 2000 B5 / 1.G APB Engine Evaporative Emission Syst

24-136

Checking voltage supply to Evaporative
Emission (EVAP) Canister Purge Regulator
Valve (solenoid valve)

Note:
The Evaporative Emission (EVAP) Canister
Purge Regulator Valve receives its power supply
via the fuel pump relay.

Test requirements

Fuse for EVAP valve OK

- Disconnect harness connector on Evaporative
Emission (EVAP) Canister Purge Regulator
Valve -N80.

The diode test lamp should light up.
If diode test lamp does not light up:
Electrical Wiring Diagrams, Troubleshooting & Component Locations - Connect VAG1527 diode test lamp between engine Ground (GND) and
socket 1 on connector.
- Operate starter.
- Check continuity of wiring from socket 1 to fuel pump relay via fuse.
Repair open circuit if necessary.
Pa
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porative Emission
(EVAP
) system, checkin
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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e=re
pair&id=AUDI.B5.FU04.24.3

If the diode test lamp lights up, check activation Page 24
-137
. - If wiring is OK, check fuel pump relay Page 24
-54
.
Pa
ge 4 of 6 Eva
porative Emission
(EVAP
) system, checkin
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.3

24-137

Testing activation of Evaporative Emission
(EVAP) Canister Purge Regulator Valve

The diode test lamp should blink.
If the diode test lamp does not blink or lights up continuously: - Connect VAG1527 between diode test lamp sockets 1 (B+) and 2 of
harness connector.
- Start output Diagnostic Test Mode (DTM) and select Evaporative
Emission (EVAP) Canister Purge Regulator Valves -N80 Page 01
-
75
. (To initiate DTM a second time, the engine must be started and
switched off)

- Connect VAG1598/31 test box to multi-pin harness connector for
engine control module. Do not connect to the engine control module
itself Page 24
-20
.
Pa
ge 5 of 6 Eva
porative Emission
(EVAP
) system, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.3

24-138
If the diode test lamp lights up continuously:

If the diode test lamp does not flash:
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If no short circuit or open circuit is found - Check for short circuit to Ground (GND) in wiring between contact 2 on
EVAP valve harness connector and socket 64 on test box.
- Check for open circuit as well as short circuit to B+ in wiring between
contact 2 on EVAP valve harness connector and socket 64 on test box.
Resistance in wiring: max. 1.5 ohm- If necessary, repair short circuit to Ground (GND) or open circuit.
- Replace Motronic Engine Control Module (ECM) -J220 Page 24
-24
.
Pa
ge 6 of 6 Eva
porative Emission
(EVAP
) system, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.3