2001 INFINITI QX4 Factory Service Manual

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INFINITI QX4 2001  Factory Service Manual On Board Diagnosis LogicNBEC0349Malfunction is detected when an improper voltage signal is sent to
ECM through vacuum cut valve bypass valve.
Possible CauseNBEC0592IHarness or connectors
(The vacuum c

Page 1122 of 2395

INFINITI QX4 2001  Factory Service Manual Wiring DiagramNBEC0351
MEC972C
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P1490 VACUUM CUT VALVE BYPASS VALVE (CIRCUIT)
Wiring Diagram
EC-587

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INFINITI QX4 2001  Factory Service Manual Diagnostic ProcedureNBEC0352
1 INSPECTION START
Do you have CONSULT-II?
YesorNo
Ye s©GO TO 2.
No©GO TO 3.
2 CHECK VACUUM CUT VALVE BYPASS VALVE CIRCUIT
With CONSULT-II
1. Turn ignition switch ªOFF

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INFINITI QX4 2001  Factory Service Manual 3 CHECK VACUUM CUT VALVE BYPASS VALUE POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect vacuum cut valve bypass valve harness connector.
SEF485T
3. Turn ignition switch ªONº.
4. Ch

Page 1125 of 2395

INFINITI QX4 2001  Factory Service Manual 6 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors B152, B151 and B101, B43
IHarness connectors B1, M2 and M94, F27
IHarness for open or short between vacuum cut valve bypass valve

Page 1126 of 2395

INFINITI QX4 2001  Factory Service Manual SEF485T
DescriptionNBEC0353COMPONENT DESCRIPTIONNBEC0353S01The vacuum cut valve and vacuum cut valve bypass valve are
installed in parallel on the EVAP purge line between the fuel tank
and the EVAP ca

Page 1127 of 2395

INFINITI QX4 2001  Factory Service Manual On Board Diagnosis LogicNBEC0356Malfunction is detected when vacuum cut valve bypass valve does
not operate properly.
Possible CauseNBEC0593IVacuum cut valve bypass valve
IVacuum cut valve
IBypass hos

Page 1128 of 2395

INFINITI QX4 2001  Factory Service Manual RESULTSº. If ªNGº is displayed, refer to ªDiagnostic
Procedureº, EC-595.
SEF530Q
Overall Function CheckNBEC0358Use this procedure to check the overall function of vacuum cut
valve bypass valve. D