2001 INFINITI QX4 stop start

17 ADJUSTMENT THROTTLE POSITION SWITCH CLOSED POSITION-II
1. Temporarily tighten sensor body fixing bolts as follows.
IGradually move the sensor body clockwise and stop it when the continuity comes to exist, then temporarily
tighten sensor body fixing bolts.
SEF954Y
2. Make sure two or three times that the continuity exists when the throttle valve is closed and continuity does not exist
when it is opened.
3. Remove 0.05 mm (0.0020 in) feeler gauge then insert 0.15 mm (0.0059 in) feeler gauge.
4. Make sure two or three times that the continuity does not exist when the throttle valve is closed.
5. Tighten throttle position sensor.
6. Check the continuity again.
Continuity does not exist while closing the throttle valve.
OK or NG
OK©GO TO 18.
NG©GO TO 16.
18 RESET THROTTLE POSITION SENSOR IDLE POSITION MEMORY
NOTE:
Always warm up engine to normal operating temperature. If engine is cool, the throttle position sensor idle posi-
tion memory will not be reset correctly.
1. Confirm that proper vacuum is applied. Refer to Test No. 10.
2. Attach blind cap to vacuum port from which vacuum hose to throttle opener was disconnected.
3. Start engine.
4. Warm up engine to normal operating temperature.
5. Stop engine. (Turn ignition switch ªOFFº.)
6. Turn ignition switch ªONº and wait at least 5 seconds.
SEF864V
7. Turn ignition switch ªOFFº and wait at least 10 seconds.
8. Repeat steps 6 and 7, 20 times.
©GO TO 19.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Basic Inspection (Cont'd)
EC-111

MONITOR ITEM CONDITION SPECIFICATION
VHCL SPEED SEITurn drive wheels and compare speedometer indication with the CON-
SULT-II valueAlmost the same speed as
the CONSULT-II value
BATTERY VOLTIIgnition switch: ON (Engine stopped) 11 - 14V
THRTL POS SENIEngine: After warming up, idle
the engineThrottle valve: fully closed 0.15 - 0.85V
IEngine: After warming up
IIgnition switch: ON
(Engine stopped)Throttle valve: fully opened 3.5 - 4.7V
START SIGNALIIgnition switch: ON,START,ON OFF,ON,OFF
CLSD THL POS
CLSD THL/P SWIEngine: After warming up, idle
the engineThrottle valve: Idle position ON
Throttle valve: Slightly open OFF
AIR COND SIGIEngine: After warming up, idle
the engineAir conditioner switch: ªOFFº OFF
Air conditioner switch: ªONº
(Compressor operates.)ON
P/N POSI SWIIgnition switch: ONShift lever: ªPº or ªNº ON
Except above OFF
PW/ST SIGNALIEngine: After warming up, idle
the engineSteering wheel in neutral position
(forward direction)OFF
The steering wheel is turned ON
IGNITION SWIIgnition switch: ON,OFF,ON ON,OFF,ON
INJ PULSE-B2
INJ PULSE-B1IEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 2.4 - 3.2 msec
2,000 rpm 1.9 - 2.8 msec
B/FUEL SCHDLIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 2.0 - 3.2 msec
2,000 rpm 1.4 - 2.6 msec
IGN TIMINGIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 15ɱ5É BTDC
2,000 rpm More than 25É BTDC
IACV-AAC/VIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 2 - 10 step
2,000 rpm Ð
PURG VOL C/VIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 0 %
2,000 rpm Ð
A/F ALPHA-B2
A/F ALPHA-B1IEngine: After warming upMaintaining engine speed at 2,000
rpm54 - 155%
EVAP SYS PRESIIgnition switch: ON Approx. 3.4V
AIR COND RLYIAir conditioner switch: OFF,ON OFF,ON
FUEL PUMP RLYIIgnition switch is turned to ON (Operates for 5 seconds)
IEngine running and crankingON
Except as shown above OFF
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
CONSULT-II Reference Value in Data Monitor Mode (Cont'd)
EC-123

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
2 R/GHeated oxygen sensor
1 (front) (bank 2)
heater[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)
3 L/ORHeated oxygen sensor
1 (front) (bank 1)
heater[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)
4 R/WHeated oxygen sensor
2 (rear) (bank 2)
heater[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)
5 P/BHeated oxygen sensor
2 (rear) (bank 1)
heater[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)
6
7
8
17PU/G
GY
Y
GY/LIACV-AAC valve[Engine is running]
IIdle speed0.1 - 14V
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
ECM Terminals and Reference Value (Cont'd)
EC-128

SEF058Y
PROCEDURE FOR MALFUNCTION ANBEC0054S01With CONSULT-IINBEC0054S01011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 6 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-155.
With GSTNBEC0054S0102Follow the procedure ªWith CONSULT-IIº above.
SEF058Y
PROCEDURE FOR MALFUNCTION B AND ENBEC0054S02With CONSULT-IINBEC0054S02011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and wait 5 seconds at most.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-155.
With GSTNBEC0054S0202Follow the procedure ªWith CONSULT-IIº above.
NOTE:
If 1st trip DTC is confirmed after more than 5 seconds, there may
be malfunction C.
SEF174Y
PROCEDURE FOR MALFUNCTION CNBEC0054S03NOTE:
If engine will not start or stops soon, wait at least 10 seconds with
engine stopped (Ignition switch ªONº) instead of running engine at
idle speed.
With CONSULT-IINBEC0054S03011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and warm it up to normal operating temperature.
4) Run engine for at least 10 seconds at idle speed.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-155.
With GSTNBEC0054S0302Follow the procedure ªWith CONSULT-IIº above.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
DTC Confirmation Procedure (Cont'd)
EC-152

8 CHECK THROTTLE POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 91 and throttle position sensor terminal 2.
Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK (With CONSULT-II)©GO TO 9.
OK (Without CONSULT-
II)©GO TO 10.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
9 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 ±40.0kPa (±300mmHg, ±11.81inHg)] 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 12.
NG©GO TO 11.
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DTC P0120 THROTTLE POSITION SENSOR
Diagnostic Procedure (Cont'd)
EC-183

10 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 12.
NG©GO TO 11.
11 ADJUST CLOSED THROTTLE POSITION SWITCH
Adjust closed throttle position switch. Refer to ªBasic Inspectionº, EC-101.
MTBL0655
OK or NG
OK©GO TO 12.
NG©Replace throttle position sensor. To adjust it, perform ªBasic Inspectionº, EC-101.
DTC P0120 THROTTLE POSITION SENSOR
Diagnostic Procedure (Cont'd)
EC-184

Possible CauseNBEC0431IHarness or connectors
(High resistance in the circuit)
IEngine coolant temperature sensor
IThermostat
SEF174Y
DTC Confirmation ProcedureNBEC0083CAUTION:
Be careful not to overheat engine.
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.
WITH CONSULT-IINBEC0083S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Check that ªCOOLAN TEMP/Sº is above 10ÉC (50ÉF).
If it is above 10ÉC (50ÉF), the test result will be OK.
If it is below 10ÉC (50ÉF), go to following step.
4) Start engine and run it for 65 minutes at idle speed.
If ªCOOLAN TEMP/Sº increases to more than 10ÉC (50ÉF)
within 65 minutes, stop engine because the test result will
be OK.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-190.
WITH GSTNBEC0083S02Follow the procedure ªWITH CONSULT-IIº above.
DTC P0125 ENGINE COOLANT TEMPERATURE SENSOR (ECTS)
Possible Cause
EC-188

SEF334Z
SEF335Z
SEF651Y
WITH CONSULT-IINBEC0098S011) Start engine and warm it up to normal operating temperature.
2) Stop engine and wait at least 10 seconds.
3) Turn ignition switch ªONº and select ªHO2S1 (B1)/(B2) P0131/
P0150º of ªHO2S1º in ªDTC WORK SUPPORTº mode with
CONSULT-II.
4) Touch ªSTARTº.
5) Start engine and let it idle for at least 3 minutes.
NOTE:
Never raise engine speed above 3,600 rpm after this step. If
the engine speed limit is exceeded, return to step 5.
6) When the following conditions are met, ªTESTINGº will be dis-
played on the CONSULT-II screen. Maintain the conditions
continuously until ªTESTINGº changes to ªCOMPLETEDº. (It
will take approximately 50 seconds or more.)
ENG SPEED 1,300 - 2,800 rpm
Vehicle speed 80 - 100 km/h (50 - 62 MPH)
B/FUEL SCHDL 3 - 10 msec
Selector lever Suitable position
If ªTESTINGº is not displayed after 5 minutes, retry from
step 2.
7) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº. If ªNGº is displayed, refer to ªDiagnostic
Procedureº, EC-205.
SEF308XB
Overall Function CheckNBEC0099Use this procedure to check the overall function of the heated oxy-
gen sensor 1 (front) circuit. During this check, a 1st trip DTC might
not be confirmed.
WITH GSTNBEC0099S011) Start engine and warm it up to normal operating temperature.
2) Set voltmeter probes between ECM terminal 63 (HO2S1 bank
1 right signal) or 62 (HO2S1 bank 2 left signal) and engine
ground.
3) Check one of the following with engine speed held at 2,000
rpm constant under no load.
IThe maximum voltage is over 0.6V at least one time.
IThe minimum voltage is over 0.1V at least one time.
4) If NG, go to ªDiagnostic Procedureº, EC-205.
DTC P0131, P0151 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(LEAN SHIFT MONITORING)
DTC Confirmation Procedure (Cont'd)
EC-204