Page 1012 of 2395
7 CHECK SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
With CONSULT-II
1. Reconnect the disconnected harness connectors.
2. Start engine and let it idle.
3. Remove vacuum hose connected to swirl control valve actuator.
4. Select ªSWIRL CONT SOL/Vº in ªACTIVE TESTº mode with CONSULT-II.
5. Touch ªONº and ªOFFº on CONSULT-II screen.
6. Check vacuum existence and operation delay time under the following conditions.
SEF004Z
Without CONSULT-II
1. Reconnect ECM harness connector.
2. Remove vacuum hose connected to swirl control valve actuator.
3. Start engine and let it idle.
4. Apply 12V of direct current between swirl control valve control solenoid valve terminals 1 and 2.
5. Check vacuum existence and operation delay time under the following conditions.
SEF005Z
OK or NG
OK©GO TO 8.
NG©Replace intake manifold collector assembly.
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DTC P1130 SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-477
Page 1015 of 2395
11 CHECK THROTTLE POSITION SENSOR
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine (ignition switch OFF).
3. Remove the vacuum hose connected to the throttle opener.
4. Connect suitable vacuum hose to the vacuum pump and the opener.
5. Apply vacuum [more than þ40.0 kPa (þ300 mmHg, þ11.81 inHg)] until the throttle drum becomes free from the rod of
the throttle opener.
SEF793W
6. Turn ignition switch ON.
7. Select ªDATA MONITORº mode with CONSULT-II.
8. Check voltage of ªTHRTL POS SENº under the following conditions.
Voltage measurement must be made with throttle position sensor installed in vehicle.
SEF062Y
OK or NG
OK©GO TO 14.
NG©GO TO 13.
DTC P1130 SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-480
Page 1018 of 2395
![INFINITI QX4 2001 Factory Service Manual TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
89 ORIntake valve timing
control position sen-
sors (LH)[Engine is running]
IWarm-up condition
IIdle speedApproximately 0.5V
SEF351Z
[Engine is INFINITI QX4 2001 Factory Service Manual TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
89 ORIntake valve timing
control position sen-
sors (LH)[Engine is running]
IWarm-up condition
IIdle speedApproximately 0.5V
SEF351Z
[Engine is](/manual-img/42/57027/w960_57027-1017.png)
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
89 ORIntake valve timing
control position sen-
sors (LH)[Engine is running]
IWarm-up condition
IIdle speedApproximately 0.5V
SEF351Z
[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.Approximately 0.5V
SEF352Z
On Board Diagnosis LogicNBEC0708Malfunction is detected when an excessively high or low voltage
from the sensor is sent to ECM.
Possible CauseNBEC0709IHarness or connectors
(Intake valve timing control position sensor circuit is open or
shorted)
IIntake valve timing control position sensor.
ICrankshaft position sensor (REF)
ICrankshaft position sensor (POS)
ICamshaft position sensor (PHASE)
SEF353Z
DTC Confirmation ProcedureNBEC0710NOTE:
If ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
10 seconds before conducting the next test.
WITH CONSULT-IINBEC0710S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Maintain the following conditions for at least 10 seconds.
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DTC P1140 (RIGHT, -B1), P1145 (LEFT, -B2) INTAKE VALVE TIMING CONTROL
POSITION SENSOR (CIRCUIT)
ECM Terminals and Reference Value (Cont'd)
EC-483
Page 1026 of 2395

On Board Diagnosis LogicNBEC0282HThe closed loop control has the one trip detection logic.
Malfunction is detected when the closed loop control function for
right bank does not operate even when vehicle is driving in the
specified condition, the closed loop control function for left bank
does not operate even when vehicle is driving in the specified
condition.
Possible CauseNBEC0531IThe front heated oxygen sensor circuit is open or shorted.
IHeated oxygen sensor 1 (front)
IHeated oxygen sensor 1 heater (front)
DTC Confirmation ProcedureNBEC0283CAUTION:
Always drive vehicle at a safe speed.
NOTE:
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:
INever raise engine speed above 3,600 rpm during the
ªDTC Confirmation Procedureº. If the engine speed limit is
exceeded, retry the procedure from step 2.
IBefore performing the following procedure, confirm that
battery voltage is more than 11V at idle.
SEF063Y
WITH CONSULT-IINBEC0283S011) Start engine and warm it up to normal operating temperature.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Hold engine speed at 2,000 rpm and check one of the follow-
ing.
IªHO2S1 (B1)/(B2)º voltage should go above 0.70V at least
once.
IªHO2S1 (B1)/(B2)º voltage should go below 0.21V at least
once.
If the check result is NG, perform ªDiagnosis Procedureº,
EC-492.
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DTC P1148 (RIGHT BANK, -B1), P1168 (LEFT BANK, -B2) CLOSED LOOP
CONTROL
On Board Diagnosis Logic
EC-491
Page 1029 of 2395

On Board Diagnosis LogicNBEC0535Malfunction is detected when the swirl control valve control vacuum
check switch remains ªOFFº under specified engine conditions.
Possible CauseNBEC0536IHarness or connectors
(Swirl control valve control vacuum check switch circuit is
open.)
IHoses
(Hoses are clogged or connected incorrectly.)
ISwirl control valve control solenoid valve
ISwirl control valve control vacuum check switch
SEF058Y
DTC Confirmation ProcedureNBEC0537NOTE:
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:
For best results, perform the test at a temperature above 5ÉC
(41ÉF).
WITH CONSULT-IINBEC0537S011) Turn ignition switch ªOFFº and wait at least 10 seconds.
2) Turn ignition switch ªONº.
3) Select ªDATA MONITORº mode with CONSULT-II and wait at
least 5 seconds.
If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-496.
WITH GSTNBEC0537S02Follow the procedure ªWITH CONSULT-IIº above.
DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
On Board Diagnosis Logic
EC-494
Page 1033 of 2395

6 CHECK SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
With CONSULT-II
1. Reconnect the disconnected harness connectors.
2. Start engine and let it idle.
3. Remove vacuum hose connected to swirl control valve actuator.
4. Select ªSWIRL CONT SOL/Vº in ªACTIVE TESTº mode with CONSULT-II.
5. Touch ªONº and ªOFFº on CONSULT-II screen.
6. Check vacuum existence and operation delay time under the following conditions.
SEF004Z
Without CONSULT-II
1. Reconnect ECM harness connector.
2. Remove vacuum hose connected to swirl control valve actuator.
3. Start engine and let it idle.
4. Apply 12V of direct current between swirl control valve control solenoid valve terminals and 2.
5. Check vacuum existence and operation delay time under the following conditions.
SEF005Z
OK or NG
OK©GO TO 7.
NG©Replace intake manifold collector assembly.
7 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
Diagnostic Procedure (Cont'd)
EC-498
Page 1035 of 2395

Possible CauseNBEC0572IHarness or connectors (The ignition primary circuit is open or
shorted.)
IPower transistor unit built into ignition coil
ICondenser
ICrankshaft position sensor (REF)
ICrankshaft position sensor (REF) circuit
SEF058Y
DTC Confirmation ProcedureNBEC0289NOTE:
IIf ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
10 seconds before conducting the next test.
IIf DTC P1320 is displayed with DTC P0335, P0340, P1335
or P1336, perform trouble diagnosis for DTC P0335,
P0340, P1335 or P1336 first. Refer to EC-334, EC-342,
EC-510 or EC-517.
WITH CONSULT-IINBEC0289S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine. (If engine does not run, turn ignition switch to
ªSTARTº for at least 5 seconds.)
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-504.
WITH GSTNBEC0289S02Follow the procedure ªWITH CONSULT-IIº above.
DTC P1320 IGNITION SIGNAL
Possible Cause
EC-500
Page 1046 of 2395

On Board Diagnosis LogicNBEC0576Malfunction is detected when
(Malfunction A)120É signal is not entered to ECM for the first few
seconds during engine cranking,
(Malfunction B)120É signal is not entered to ECM during engine
running,
(Malfunction C)120É signal cycle excessively changes during
engine running.
FAIL-SAFE MODENBEC0576S01When the ECM enters the fail-safe mode, the MIL illuminates.
Detected items Engine operating condition in fail-safe mode
Crankshaft position sensor (REF)
circuitCompression TDC signal (120É signal) is controlled by camshaft position sensor (PHASE)
signal and crankshaft position sensor (POS) signal. Ignition timing will be delayed 0É to 2É.
Possible CauseNBEC0577IHarness or connectors
(The crankshaft position sensor (REF) circuit is open or
shorted.)
ICrankshaft position sensor (REF)
IStarter motor (Refer to SC section.)
IStarting system circuit (Refer to SC section.)
IDead (Weak) battery
DTC Confirmation ProcedureNBEC0578NOTE:
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 ANBEC0578S01With CONSULT-IINBEC0578S01011) 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-514.
With GSTNBEC0578S0102Follow the procedure ªWith CONSULT-IIº above.
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DTC P1335 CRANKSHAFT POSITION SENSOR (CKPS) (REF)
On Board Diagnosis Logic
EC-511