Page 775 of 2395

DescriptionNBEC0123SYSTEM DESCRIPTIONNBEC0123S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speedHeated
oxygen
sensor 1
heater
(front) con-
trolHeated oxygen sensor 1 heat-
ers (front)
Crankshaft position sensor (REF)
The ECM performs ON/OFF control of the heated oxygen sensor 1 heaters (front) corresponding to the engine
speed.
OPERATIONNBEC0123S02
Engine speed rpm Heated oxygen sensor 1 heaters (front)
Above 3,600 OFF
Below 3,600 ON
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0124Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 HTR (B1)
HO2S1 HTR (B2)IEngine speed: Below 3,600 rpm ON
IEngine speed: Above 3,600 rpm OFF
ECM Terminals and Reference ValueNBEC0657Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
3 L/ORHeated oxygen sensor
1 heater (front) (bank
1)[Engine is running]
IEngine speed is below 3,600 rpm.0 - 1.0V
[Engine is running]
IEngine speed is above 3,600 rpm.BATTERY VOLTAGE
(11 - 14V)
2 R/GHeated oxygen sensor
1 heater (front) (bank
2)[Engine is running]
IEngine speed is below 3,600 rpm.0 - 1.0V
[Engine is running]
IEngine speed is above 3,600 rpm.BATTERY VOLTAGE
(11 - 14V)
DTC P0135, P0155 HEATED OXYGEN SENSOR 1 HEATER (FRONT) (BANK
1)/(BANK 2)
Description
EC-240
Page 821 of 2395

DescriptionNBEC0162SYSTEM DESCRIPTIONNBEC0162S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speedHeated
oxygen
sensor 2
heater
(rear) con-
trolHeated oxygen sensor 2 heat-
ers (rear)
Crankshaft position sensor (REF)
The ECM performs ON/OFF control of the heated oxygen sensor 2 heaters (rear) corresponding to the engine
speed.
OPERATIONNBEC0162S02
Engine speed rpm Heated oxygen sensor 2 heaters (rear)
Above 3,200 OFF
Below 3,200 ON
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0163Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)IIgnition switch: ON (Engine stopped)
IEngine is running above 3,200 rpm.OFF
IEngine is running below 3,200 rpm after driving for 2 minutes at a
speed of 70 km/h (43 MPH) or more.ON
ECM Terminals and Reference ValueNBEC0662Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
5 P/BHeated oxygen sensor
2 heater (rear) (bank
1)[Engine is running]
IEngine speed is below 3,200 rpm.
IAfter driving for 2 minutes at a speed of 70 km/h
(43 MPH) or more.0 - 1.0V
[Ignition switch ªONº]
IEngine stopped
[Engine is running]
IEngine speed is above 3,200 rpm.BATTERY VOLTAGE
(11 - 14V)
4 R/WHeated oxygen sensor
2 heater (rear) (bank
2)[Engine is running]
IEngine speed is below 3,200 rpm.
IAfter driving for 2 minutes at a speed of 70 km/h
(43 MPH) or more.0 - 1.0V
[Ignition switch ªONº]
IEngine stopped
[Engine is running]
IEngine speed is above 3,200 rpm.BATTERY VOLTAGE
(11 - 14V)
DTC P0141, P0161 HEATED OXYGEN SENSOR 2 HEATER (REAR) (BANK 1)/
(BANK 2)
Description
EC-286
Page 870 of 2395

ECM Terminals and Reference Value=NBEC0664Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
85 YCrankshaft position
sensor (POS)[Engine is running]
IIdle speedApproximately 2.4V
SEF057V
[Engine is running]
IEngine speed is 2,000 rpm.Approximately 2.3V
SEF058V
On Board Diagnosis LogicNBEC0193Malfunction is detected when 1É signal is not entered to ECM for
the first few seconds during engine cranking, or 1É signal is not
entered to ECM during engine running.
Possible CauseNBEC0493IHarness or connectors
(The crankshaft position sensor (POS) circuit is open or
shorted.)
ICrankshaft position sensor (POS)
IStarter motor (Refer to EL section.)
IStarting system circuit (Refer to EL section.)
IDead (Weak) battery
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0335 CRANKSHAFT POSITION SENSOR (CKPS) (POS)
ECM Terminals and Reference Value
EC-335
Page 878 of 2395
![INFINITI QX4 2001 Factory Service Manual Possible CauseNBEC0494IHarness or connectors
[The camshaft position sensor (PHASE) circuit is open or
shorted.]
ICamshaft position sensor (PHASE)
IStarter motor (Refer to SC section.)
IStarting system INFINITI QX4 2001 Factory Service Manual Possible CauseNBEC0494IHarness or connectors
[The camshaft position sensor (PHASE) circuit is open or
shorted.]
ICamshaft position sensor (PHASE)
IStarter motor (Refer to SC section.)
IStarting system](/manual-img/42/57027/w960_57027-877.png)
Possible CauseNBEC0494IHarness or connectors
[The camshaft position sensor (PHASE) circuit is open or
shorted.]
ICamshaft position sensor (PHASE)
IStarter motor (Refer to SC section.)
IStarting system circuit (Refer to SC section.)
IDead (Weak) battery
DTC Confirmation ProcedureNBEC0200NOTE:
IPerform ªPROCEDURE FOR MALFUNCTION Aº first. If 1st
trip DTC cannot be confirmed, perform ªPROCEDURE
FOR MALFUNCTION B AND Cº.
IIf ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 10.5V at idle.
SEF013Y
PROCEDURE FOR MALFUNCTION ANBEC0200S01With CONSULT-IINBEC0200S01011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Crank engine for at least 2 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-345.
With GSTNBEC0200S0102Follow the procedure ªWith CONSULT-IIº above.
SEF058Y
PROCEDURE FOR MALFUNCTION B AND CNBEC0200S02With CONSULT-IINBEC0200S02011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and run it for at least 2 seconds at idle speed.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-345.
With GSTNBEC0200S0202Follow the procedure ªWith CONSULT-IIº above.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0340 CAMSHAFT POSITION SENSOR (CMPS) (PHASE)
Possible Cause
EC-343
Page 903 of 2395

ECM Terminals and Reference ValueNBEC0666Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 L/YEVAP canister purge
volume control sole-
noid valve[Engine is running]
IIdle speedBATTERY VOLTAGE
(11 - 14V)
SEF994U
[Engine is running]
IEngine speed is about 2,000 rpm (More than 100
seconds after starting engine).BATTERY VOLTAGE
(11 - 14V)
SEF995U
On Board Diagnosis LogicNBEC0224Malfunction is detected when an improper voltage signal is sent to
ECM through the valve.
Possible CauseNBEC0511IHarness or connectors
(The valve circuit is open or shorted.)
IEVAP canister purge volume control solenoid valve
DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
(CIRCUIT)
ECM Terminals and Reference Value
EC-368
Page 904 of 2395
SEF058Y
DTC Confirmation ProcedureNBEC0225NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm battery
voltage is more than 11V at idle.
WITH CONSULT-IINBEC0225S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and let it idle for at least 13 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-371.
WITH GSTNBEC0225S02Follow the proocedure ªWITH CONSULT-IIº above.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
(CIRCUIT)
DTC Confirmation Procedure
EC-369
Page 909 of 2395

SEF032W
SEF143S
Component DescriptionNBEC0228The EVAP canister vent control valve is located on the EVAP can-
ister and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is ener-
gized. A plunger will then move to seal the canister vent. The abil-
ity to seal the vent is necessary for the on board diagnosis of other
evaporative emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the
evaporative emission control system is depressurized and allows
ªEVAP Control System (Small Leak)º diagnosis.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0229Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/VIIgnition switch: ON OFF
ECM Terminals and Reference ValueNBEC0667Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
40 G/YEVAP canister vent
control valve[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNBEC0231Malfunction is detected when an improper voltage signal is sent to
ECM through EVAP canister vent control valve.
DTC P0446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CIRCUIT)
Component Description
EC-374
Page 910 of 2395
Possible CauseNBEC0512IHarness or connectors
(The valve circuit is open or shorted.)
IEVAP canister vent control valve
DTC Confirmation ProcedureNBEC0232NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm battery
voltage is more than 11V at idle.
SEF058Y
WITH CONSULT-IINBEC0232S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and wait at least 8 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-377.
WITH GSTNBEC0232S02Follow the procedure ªWITH CONSULT-IIº above.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CIRCUIT)
Possible Cause
EC-375