engine INFINITI QX4 2001 Factory Service Manual

SEF213Y
DTC Confirmation ProcedureNBEC0183CAUTION:
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.
WITH CONSULT-IINBEC0183S011) Turn ignition switch ªONº, and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and warm it up to normal operating temperature.
3) Turn ignition switch ªOFFº and wait at least 10 seconds.
4) Start engine again and drive at 1,500 to 3,000 rpm for at least
3 minutes.
Hold the accelerator pedal as steady as possible.
NOTE:
Refer to the freeze frame data for the test driving conditions.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-321.
WITH GSTNBEC0183S02Follow the procedure ªWith CONSULT-IIº above.
Diagnostic ProcedureNBEC0184
1 CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
OK or NG
OK©GO TO 2.
NG©Discover air leak location and repair.
2 CHECK FOR EXHAUST SYSTEM CLOGGING
1. Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
OK or NG
OK©GO TO 3.
NG©Repair or replace it.
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DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
DTC Confirmation Procedure
EC-321

3 PERFORM POWER BALANCE TEST
With CONSULT-II
1. Perform ªPOWER BALANCEº in ªACTIVE TESTº mode.
SEF190Y
2. Is there any cylinder which does not produce a momentary engine speed drop?
Without CONSULT-II
When disconnecting each ignition coil harness connector one at a time, is there any cylinder which does not produce a
momentary engine speed drop?
SEF975Y
YesorNo
Ye s©GO TO 5.
No©GO TO 4.
4 CHECK INJECTOR
Does each injector make an operating sound at idle?
MEC703B
YesorNo
Ye s©GO TO 5.
No©Check injector(s) and circuit(s). Refer to EC-616.
DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
Diagnostic Procedure (Cont'd)
EC-322

5 CHECK IGNITION SPARK
1. Disconnect ignition wire from spark plug.
2. Connect a known good spark plug to the ignition wire.
3. Place end of spark plug against a suitable ground and crank engine.
4. Check for spark.
SEF575Q
OK or NG
OK©GO TO 6.
NG©Check ignition coil, power transistor and their circuits. Refer to ªDTC P1320 IGNITION
SIGNALº, EC-499
6 CHECK SPARK PLUGS
Remove the spark plugs and check for fouling, etc.
SEF156I
OK or NG
OK©GO TO 7.
NG©Repair or replace spark plug(s) with standard type one(s). For spark plug type, refer to
MA-13, ªENGINE MAINTENANCEº.
7 CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-14, ªMeasurement of Compression Pressureº.
Standard:
1,275 kPa (13.0 kg/cm
2, 185 psi)/300 rpm
Minimum:
981 kPa (10.0 kg/cm
2, 142 psi)/300 rpm
Difference between each cylinder:
98 kPa (1.0 kg/cm
2, 14 psi)/300 rpm
OK or NG
OK©GO TO 8.
NG©Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
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DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
Diagnostic Procedure (Cont'd)
EC-323

11 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 ªHI SPEEDº in ªDATA MONITORº mode with CONSULT-II, and select ªHO2S1 (B1)/(B2)º and
ªHO2S1 MNTR (B1)/(B2)º.
3. Hold engine speed at 2,000 rpm under no load during the following steps.
4. Touch ªRECORDº on CONSULT-II screen.
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5. 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 left:
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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 14.
NG©GO TO 13.
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DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
Diagnostic Procedure (Cont'd)
EC-325

12 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 14.
NG©GO TO 13.
13 REPLACE HEATED OXYGEN SENSOR 1 (FRONT)
1. Turn ignition switch ªOFFº.
2. Check heated oxygen sensor 1 (front) harness protector color.
SEF505Y
©Replace malfunctioning heated oxygen sensor 1 (front).
DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
Diagnostic Procedure (Cont'd)
EC-326

14 CHECK MASS AIR FLOW SENSOR
With CONSULT-II
Check mass air flow sensor signal in ªDATA MONITORº mode with CONSULT-II.
2.0 - 6.0 g´m/sec: at idling
7.0 - 20.0 g´m/sec: at 2,500 rpm
With GST
Check mass air flow sensor signal in MODE 1 with GST.
2.0 - 6.0 g´m/sec: at idling
7.0 - 20.0 g´m/sec: at 2,500 rpm
OK or NG
OK©GO TO 15.
NG©Check connectors for rusted terminals or loose connections in the mass air flow sensor
circuit or engine grounds. Refer to EC-150.
15 CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in ªSymptom Matrix Chartº, EC-118.
OK or NG
OK©GO TO 16.
NG©Repair or replace.
16 ERASE THE 1ST TRIP DTC
Erase the 1st trip DTC from the ECM memory after performing the tests. Refer to EC-72.
Some tests may cause a 1st trip DTC to be set.
©GO TO 17.
17 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
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DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
Diagnostic Procedure (Cont'd)
EC-327

SEF332I
Component DescriptionNBEC0185The knock sensor is attached to the cylinder block. It senses
engine knocking using a piezoelectric element. A knocking vibration
from the cylinder block is sensed as vibrational pressure. This
pressure is converted into a voltage signal and sent to the ECM.
Freeze frame data will not be stored in the ECM for the knock
sensor. The MIL will not light for knock sensor malfunction.
The knock sensor has one trip detection logic.
ECM Terminals and Reference ValueNBEC0663Specification 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)
93 W Knock sensor[Engine is running]
IIdle speedApproximately 2.5V
On Board Diagnosis LogicNBEC0187Malfunction is detected when an excessively low or high voltage
from the knock sensor is sent to ECM.
Possible CauseNBEC0491IHarness or connectors
(The knock sensor circuit is open or shorted.)
IKnock sensor
SEF058Y
DTC Confirmation ProcedureNBEC0188NOTE:
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 that bat-
tery voltage is more than 10V at idle.
DTC P0325 KNOCK SENSOR (KS)
Component Description
EC-328

WITH CONSULT-IINBEC0188S011) Turn ignition switch ªONº and select ªDATA MONITORº mode
with CONSULT-II
2) Start engine and run it for at least 5 seconds at idle speed.
3) If DTC is detected, go to ªDiagnostic Procedureº, EC-331.
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DTC P0325 KNOCK SENSOR (KS)
DTC Confirmation Procedure (Cont'd)
EC-329

Diagnostic ProcedureNBEC0190
1 CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check resistance between ECM terminal 93 and engine ground.
NOTE:
It is necessary to use an ohmmeter which can measure more than 10 MW.
SEF321X
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG©GO TO 2.
2 CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect knock sensor harness connector.
2. Check harness continuity between ECM terminal 93 and knock 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©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F19, F116
IHarness for open or short between ECM and knock sensor
©Repair open circuit or short to ground or short to power in harness or connectors.
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DTC P0325 KNOCK SENSOR (KS)
Diagnostic Procedure
EC-331

4 CHECK KNOCK SENSOR
Check resistance between knock sensor terminal 2 and ground.
NOTE:
It is necessary to use an ohmmeter which can measure more than 10 MW.
SEF976Y
CAUTION:
Do not use any knock sensors that have been dropped or physically damaged. Use only new ones.
OK or NG
OK©GO TO 8.
NG©Replace knock sensor.
5 RETIGHTEN GROUND SCREWS
Loose and retighten engine ground screws.
SEF959Y
©GO TO 6.
6 CHECK KNOCK SENSOR SHIELD CIRCUIT FOR OPEN AND SHORT
1. Disconnect harness connectors F19, F116.
2. Check harness continuity between harness connector F19 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 8.
NG©GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F19, F116
IHarness for open or short between harness connector F19 and engine ground
©Repair open circuit or short to power in harness or connectors.
DTC P0325 KNOCK SENSOR (KS)
Diagnostic Procedure (Cont'd)
EC-332