2001 INFINITI QX4 ignition

8 CHECK SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
1. Turn ignition switch ªOFFº.
2. Disconnect vacuum hose connected to swirl control valve control vacuum check switch.
3. Attach vacuum pump to swirl control valve control vacuum check switch.
4. Turn ignition switch ªONº.
5. Check voltage between ECM terminal 55 and ground under the following conditions.
SEF709X
OK or NG
OK©GO TO 9.
NG©Replace swirl control valve control vacuum check switch.
9 CHECK CRANKSHAFT POSITION SENSOR (REF)-I
1. Turn ignition switch ªOFFº.
2. Loosen the fixing bolts and remove the CKPS (REF).
3. Visually check the CKPS (REF) for chipping.
SEF585P
OK or NG
OK©GO TO 10.
NG©Replace crankshaft position sensor (REF).
DTC P1130 SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-478

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

12 CHECK THROTTLE POSITION SENSOR
Without 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. Check voltage between ECM terminal 91 (Throttle position sensor signal) and ground.
Voltage measurement must be made with throttle position sensor installed in vehicle.
MTBL0231
OK or NG
OK©GO TO 14.
NG©GO TO 13.
13 ADJUST CLOSED THROTTLE POSITION SWITCH
Adjust closed throttle position switch. Refer to ªBasic Inspectionº, EC-101.
MTBL0655
OK or NG
OK©GO TO 14.
NG©Replace throttle position sensor. To adjust it, perform ªBasic Inspectionº, EC-101.
14 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
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DTC P1130 SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
Diagnostic Procedure (Cont'd)
EC-481

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

Diagnostic ProcedureNBEC0712
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF959Y
©GO TO 2.
2 CHECK INTAKE VALVE TIMING CONTROL POSITION SENSOR POWER SUPPLY CIRCUIT
1. Disconnect intake valve timing control position sensor harness connector.
SEF360Z
2. Turn ignition switch ªONº.
3. Check voltage between intake valve timing control position sensor harness connector terminal 3 and ground with CON-
SULT-II or tester.
SEF370X
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 4.
NG©GO TO 3.
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DTC P1140 (RIGHT, -B1), P1145 (LEFT, -B2) INTAKE VALVE TIMING CONTROL
POSITION SENSOR (CIRCUIT)
Diagnostic Procedure
EC-487

3 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M32, F23
IHarness connectors E1, M1
IHarness for open or short between ECM and intake valve timing control position sensor
IHarness for open or short between ECM relay and intake valve timing control position sensor
©Repair open circuit or short to ground or short to power in harness or connectors.
4 CHECK INTAKE VALVE TIMING CONTROL POSITION SENSOR GROUND CIRCUIT FOR OPEN AND
SHORT
1. Turn ignition switch ªOFFº.
2. Check harness connector continuity between intake valve timing control position sensor harness connector terminal 1
and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK©GO TO 5.
NG©Repair open circuit or short to power in harness or connectors.
5 CHECK INTAKE VALVE TIMING CONTROL POSITION SENSOR INPUT SIGNAL CIRCUIT
1. Disconnect ECM harness connector.
2. Check harness connectors continuity between ECM terminal 79 (Right) or 89 (Left) and terminal 2. Refer to Wiring Dia-
gram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 6.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK INTAKE VALVE TIMING CONTROL POSITION SENSOR INSTALLATION
Check that intake valve timing control position sensor is installed correctly as shown below.
SEF361Z
OK or NG
OK©GO TO 7.
NG©Install intake valve timing control position sensor correclty.
DTC P1140 (RIGHT, -B1), P1145 (LEFT, -B2) INTAKE VALVE TIMING CONTROL
POSITION SENSOR (CIRCUIT)
Diagnostic Procedure (Cont'd)
EC-488

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

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