Infiniti G20 (P11). Manual — part 290

Wiring Diagram

NCEC0636

TEC720

GI

MA

EM

LC

FE

CL

MT

AT

AX

SU

BR

ST

RS

BT

HA

SC

EL

IDX

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

Wiring Diagram

EC-571

Diagnostic Procedure

NCEC0637

1

INSPECTION START

Do you have CONSULT-II?

Yes or No

Yes

©

GO TO 2.

No

©

GO TO 3.

2

CHECK VACUUM CUT VALVE BYPASS VALVE OPERATION

With CONSULT-II

1. Turn ignition switch “OFF”.
2. Remove vacuum cut valve and vacuum cut valve bypass valve as an assembly.
3. Apply vacuum to port A and check that there is no suction from port B.
4. Apply vacuum to port B and check that there is suction from port A.
5. Blow air in port B and check that there is a resistance to flow out of port A.
6. Turn ignition switch “ON”.
7. Select “VC/V BYPASS/V” in “ACTIVE TEST” mode with CONSULT-II and touch “ON”.
8. Blow air in port A and check that air flows freely out of port B.
9. Blow air in port B and check that air flows freely out of port A.

SEF808Y

OK or NG

OK

©

GO TO 4.

NG

©

GO TO 5.

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

Diagnostic Procedure

EC-572

3

CHECK VACUUM CUT VALVE BYPASS VALVE OPERATION

Without CONSULT-II

1. Turn ignition switch “OFF”.
2. Remove vacuum cut valve and vacuum cut valve bypass valve as an assembly.
3. Apply vacuum to port A and check that there is no suction from port B.
4. Apply vacuum to port B and check that there is suction from port A.
5. Blow air in port B and check that there is a resistance to flow out of port A.
6. Disconnect vacuum cut valve bypass valve harness connector.
7. Supply battery voltage to the terminal.
8. Blow air in port A and check that air flows freely out of port B.
9. Blow air in port B and check that air flows freely out of port A.

SEF914U

OK or NG

OK

©

GO TO 4.

NG

©

GO TO 7.

4

CHECK EVAP PURGE LINE

Check EVAP purge line between EVAP canister and fuel tank for clogging or disconnection.

OK or NG

OK

©

GO TO 5.

NG

©

Repair it.

5

CHECK EVAP PURGE PORT

Check EVAP purge port of fuel tank for clogging.

OK or NG

OK

©

GO TO 6.

NG

©

Clean EVAP purge port.

GI

MA

EM

LC

FE

CL

MT

AT

AX

SU

BR

ST

RS

BT

HA

SC

EL

IDX

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

Diagnostic Procedure (Cont’d)

EC-573

6

CHECK EVAP CANISTER

1. Pinch the fresh air hose.
2. Blow air into port A and check that it flows freely out of port B.

AEC630A

OK or NG

OK

©

GO TO 12.

NG

©

Replace EVAP canister.

7

CHECK BYPASS HOSE

Check bypass hoses for clogging.

OK or NG

OK

©

GO TO 8.

NG

©

Repair or replace hoses.

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

Diagnostic Procedure (Cont’d)

EC-574