engine INFINITI QX4 2001 Factory Service Manual

3) Check the following with engine speed held at 2,000 rpm con-
stant under no load.
IThe voltage does not remain in the range of 0.2 - 0.4V.
4) If NG, go to ªDiagnostic Procedureº, EC-198.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0130, P0150 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(CIRCUIT)
Overall Function Check (Cont'd)
EC-195

Diagnostic ProcedureNBEC0093
1 INSPECTION START
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF959Y
3. Make sure HO2S1 (front) harness protector color, and disconnect corresponding heated oxygen sensor 1 (front) har-
ness connector.
SEF505Y
SEF965Y
SEF966Y
©GO TO 2.
DTC P0130, P0150 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(CIRCUIT)
Diagnostic Procedure
EC-198

3 CHECK HEATED OXYGEN SENSOR 1 (FRONT)
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªMANU TRIGº and adjust ªTRIGGER POINTº to 100% in ªDATA MONITORº mode with CONSULT-II.
3. Select ªHO2S1 (B1)/(B2)º and ªHO2S1 MNTR (B1)/(B2)º.
4. Hold engine speed at 2,000 rpm under no load during the following steps.
5. Touch ªRECORDº on CONSULT-II screen.
SEF967Y
6. Check the following.
IªHO2S1 MNTR (B1)/(B2)º in ªDATA MONITORº mode changes from ªRICHº to ªLEANº to ªRICHº 5 times in 10 seconds.
5 times (cycles) are counted as shown below.
SEF647Y
IªHO2S1 (B1)/(B2)º voltage goes above 0.6V at least once.
IªHO2S1 (B1)/(B2)º voltage goes below 0.3V at least once.
IªHO2S1 (B1)/(B2)º voltage never exceeds 1.0V.
SEF648Y
CAUTION:
Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
OK or NG
OK©GO TO 6.
NG©GO TO 5.
DTC P0130, P0150 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(CIRCUIT)
Diagnostic Procedure (Cont'd)
EC-200

4 CHECK HEATED OXYGEN SENSOR 1 (FRONT)
Without CONSULT-II
1. 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 the following with engine speed held at 2,000 rpm constant under no load.
SEF967XA
CAUTION:
Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 REPLACE HEATED OXYGEN SENSOR 1 (FRONT)
1. Turn ignition switch ªOFFº.
2. Check heated oxygen sensor 1 (front) harness protector color.
SEF505Y
CAUTION:
Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool
J-43897-18 or J-43897-12 and approved anti-seize lubricant.
©Replace malfunctioning heated oxygen sensor 1 (front).
6 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0130, P0150 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(CIRCUIT)
Diagnostic Procedure (Cont'd)
EC-201

SEF463R
SEF288D
Component DescriptionNBEC0094The heated oxygen sensor 1 (front) is placed into the front tube. It
detects the amount of oxygen in the exhaust gas compared to the
outside air. The heated oxygen sensor 1 (front) has a closed-end
tube made of ceramic zirconia. The zirconia generates voltage from
approximately 1V in richer conditions to 0V in leaner conditions.
The heated oxygen sensor 1 (front) signal is sent to the ECM. The
ECM adjusts the injection pulse duration to achieve the ideal air-
fuel ratio. The ideal air-fuel ratio occurs near the radical change
from 1V to 0V.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0095Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 (B1)
HO2S1 (B2)
IEngine: After warming upMaintaining engine speed at 2,000
rpm0 - 0.3V+,Approx. 0.6 - 1.0V
HO2S1 MNTR
(B1)
HO2S1 MNTR
(B2)LEAN+,RICH
Changes more than 5 times during
10 seconds.
ECM Terminals and Reference ValueNBEC0653Specification 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)
63 GHeated oxygen sensor
1 (front) (bank 1)[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.0 - Approximately 1.0V (Peri-
odically change)
SEF059V
DTC P0131, P0151 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(LEAN SHIFT MONITORING)
Component Description
EC-202

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
62 G/BHeated oxygen sensor
1 (front) (bank 2)[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.0 - Approximately 1.0V (Peri-
odically change)
SEF059V
SEF300U
On Board Diagnosis LogicNBEC0097To judge the malfunction, the output from the heated oxygen sen-
sor 1 (front) is monitored to determine whether the ªrichº output is
sufficiently high and whether the ªleanº output is sufficiently low.
When both the outputs are shifting to the lean side, the malfunc-
tion will be detected.
Malfunction is detected when the maximum and minimum voltage
from the sensor are not reached to the specified voltages.
Possible CauseNBEC0433IHeated oxygen sensor 1 (front)
IHeated oxygen sensor 1 heater (front)
IFuel pressure
IInjectors
IIntake air leaks
DTC Confirmation ProcedureNBEC0098CAUTION:
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:
IAlways perform at a temperature above þ10ÉC (14ÉF).
IBefore performing following procedure, confirm that bat-
tery voltage is more than 11V at idle.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0131, P0151 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(LEAN SHIFT MONITORING)
ECM Terminals and Reference Value (Cont'd)
EC-203

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

Diagnostic ProcedureNBEC0100
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF959Y
©GO TO 2.
2 RETIGHTEN HEATED OXYGEN SENSOR 1 (FRONT)
Loosen and retighten corresponding heated oxygen sensor 1 (front).
Tightening torque:
40 - 60 N´m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
©GO TO 3.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0131, P0151 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(LEAN SHIFT MONITORING)
Diagnostic Procedure
EC-205

3 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARNING CONTº in ªWORK SUPPORTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªCLEARº.
SEF968Y
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure 1st trip DTC P0100 is displayed.
6. Erase the 1st trip DTC memory. Refer to ªHOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATIONº,
EC-72.
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0171, P0174. Refer to EC-294.
No©GO TO 4.
DTC P0131, P0151 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(LEAN SHIFT MONITORING)
Diagnostic Procedure (Cont'd)
EC-206

4 CHECK HEATED OXYGEN SENSOR HEATER 1 (FRONT)
1. Stop engine.
2. Check heated oxygen sensor 1 (front) harness protector color.
SEF505Y
3. Disconnect HO2S1 harness connector.
4. Check resistance between HO2S1 terminals as follows.
SEF969Y
CAUTION:
Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
OK or NG
OK (With CONSULT-II)©GO TO 5.
OK (Without CONSULT-
II)©GO TO 6.
NG©GO TO 7.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0131, P0151 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(LEAN SHIFT MONITORING)
Diagnostic Procedure (Cont'd)
EC-207