2001 NISSAN X-TRAIL spark plugs

TROUBLE DIAGNOSIS
EC-67
[QR25(WITH EURO-OBD)]
C
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TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionEBS00M0S
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose a malfunction that occurs inter-
mittently rather than continuously. Most intermittent malfunctions are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the “Work Flow” on EC-68
.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple on EC-70
should be used.
Start your diagnosis by looking for “conventional” incidents first. This
will help troubleshoot driveability incidents on an electronically con-
trolled engine vehicle.
MEF036D
SEF233G
SEF234G

EC-102
[QR25(WITH EURO-OBD)]
TROUBLE DIAGNOSIS
DATA MONITOR (SPEC) MODE
Monitored Item
NOTE:
●Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
ENG SPEED [rpm]×
●Indicates the engine speed computed
from the signals of the crankshaft posi-
tion sensor (POS) and camshaft position
sensor (PHASE).
MAS A/F SE-B1 [V]××
●The signal voltage of the mass air flow
sensor specification is displayed.●When engine is running specification
range is indicated.
B/FUEL SCHDL
[msec]
●“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
●When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]×
●The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.●When engine is running specification
range is indicated.
●This data also includes the data for the
air-fuel ratio learning control.
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION
●Engine: Return to the original
trouble condition
●Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
●Harness and connectors
●Fuel injectors
●Heated oxygen sensor 1
IGNITION TIM-
ING
●Engine: Return to the original
trouble condition
●Timing light: Set
●Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
●Perform “Idle Air Volume Learn-
ing”.
POWER BAL-
ANCE
●Engine: After warming up, idle
the engine.
●A/C switch “OFF”
●Shift lever “N”
●Cut off each injector signal one at
a time using CONSULT-II.Engine runs rough or dies.
●Harness and connectors
●Compression
●Fuel injectors
●Power transistor
●Spark plugs
●Ignition coils
COOLING FAN
●Ignition switch: ON
●Turn the cooling fan “ON” and
“OFF” with CONSULT-II.Cooling fan moves and stops.
●Harness and connectors
●Cooling fan relay
●Cooling fan motor
ENG COOLANT
TEMP
●Engine: Return to the original
trouble condition
●Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
●Harness and connectors
●Engine coolant temperature sen-
sor
●Fuel injectors
FUEL PUMP
RELAY
●Ignition switch: ON (Engine
stopped)
●Turn the fuel pump relay “ON”
and “OFF” using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.●Harness and connectors
●Fuel pump relay

EC-220
[QR25(WITH EURO-OBD)]
DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
5. CHECK IGNITION SPARK
1. Disconnect ignition coil assembly from rocker cover.
2. Connect a known-good spark plug to the ignition coil assembly.
3. Place end of spark plug against a suitable ground and crank engine.
4. Check for spark.
OK or NG
OK >> GO TO 6.
NG >> Check ignition coil, power transistor and their circuits.
Refer to EC-379, "
IGNITION SIGNAL" .
6. CHECK SPARK PLUGS
Remove the spark plugs and check for fouling, etc.
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-24, "
Checking
and Changing Spark Plugs" .
7. CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-59, "
CHECKING COMPRESSION PRESSURE" .
OK or NG
OK >> GO TO 8.
NG >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
8. CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to EC-42, "
FUEL PRESSURE RELEASE" .
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-42, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 9.
NG >> Follow the Instruction of “FUEL PRESSURE CHECK”.
SEF575Q
SEF156I
Standard:
1,190 kPa (11.9 bar, 12.1 kg/cm2 , 172 psi)/250
rpm
Minimum:
990 kPa (9.9 bar, 10.1 kg/cm
2 , 144 psi)/250 rpm
Difference between each
cylinder:98 kPa (0.98 bar, 1.0 kg/cm
2 , 14 psi)/250 rpm
At idle: Approx. 350 kPa (3.5 bar, 3.57 kg/cm
2 , 51 psi)

EC-460
[QR25(WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
PFP:00004
Trouble Diagnosis IntroductionEBS00NE9
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose a incident that occurs intermit-
tently rather than continuously. Most intermittent malfunctions are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the “Work Flow” on EC-461
.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple on EC-463
should be used.
Start your diagnosis by looking for “conventional” incidents first. This
will help troubleshoot driveability incidents on an electronically con-
trolled engine vehicle.
MEF036D
SEF233G
SEF234G

EC-494
[QR25(WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
DATA MONITOR (SPEC) MODE
Monitored Item
NOTE:
●Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
ENG SPEED [rpm]×
●Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS).
MAS A/F SE-B1 [V]××
●The signal voltage of the mass air flow
sensor specification is displayed.●When engine is running specification
range is indicated.
B/FUEL SCHDL
[msec]
●“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
●When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]×
●The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.●When engine is running specification
range is indicated.
●This data also includes the data for the
air-fuel ratio learning control.
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION
●Engine: Return to the original
trouble condition
●Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
●Harness and connectors
●Fuel injectors
●Heated oxygen sensor 1
IGNITION TIM-
ING
●Engine: Return to the original
trouble condition
●Timing light: Set
●Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
●Perform “Idle Air Volume Learn-
ing”.
POWER BAL-
ANCE
●Engine: After warming up, idle
the engine.
●A/C switch “OFF”
●Shift lever “N”
●Cut off each injector signal one at
a time using CONSULT-II.Engine runs rough or dies.
●Harness and connectors
●Compression
●Fuel injectors
●Power transistor
●Spark plugs
●Ignition coils
COOLING FAN
●Ignition switch: ON
●Turn the cooling fan “ON” and
“OFF” with CONSULT-II.Cooling fan moves and stops.
●Harness and connectors
●Cooling fan relay
●Cooling fan motor
ENG COOLANT
TEMP
●Engine: Return to the original
trouble condition
●Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
●Harness and connectors
●Engine coolant temperature sen-
sor
●Fuel injectors
FUEL PUMP
RELAY
●Ignition switch: ON (Engine
stopped)
●Turn the fuel pump relay “ON”
and “OFF” using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.●Harness and connectors
●Fuel pump relay

TROUBLE DIAGNOSIS
EC-799
[QR20(WITH EURO-OBD)]
C
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MA
EC
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionEBS00MSR
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose a malfunction that occurs inter-
mittently rather than continuously. Most intermittent malfunctions are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the “Work Flow” on EC-800
.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple on EC-802
should be used.
Start your diagnosis by looking for “conventional” incidents first. This
will help troubleshoot driveability incidents on an electronically con-
trolled engine vehicle.
MEF036D
SEF233G
SEF234G

EC-834
[QR20(WITH EURO-OBD)]
TROUBLE DIAGNOSIS
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-781, "SYSTEM READINESS TEST (SRT) CODE" .
SRT Work Support Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC Work Support Mode
POWER BAL-
ANCE
●Engine: After warming up, idle
the engine.
●A/C switch “OFF”
●Shift lever “N”
●Cut off each injector signal one at
a time using CONSULT-II.Engine runs rough or dies.
●Harness and connectors
●Compression
●Fuel injectors
●Power transistor
●Spark plugs
●Ignition coils
COOLING FAN
●Ignition switch: ON
●Turn the cooling fan “ON” and
“OFF” with CONSULT-II.Cooling fan moves and stops.
●Harness and connectors
●Cooling fan relay
●Cooling fan motor
ENG COOLANT
TEMP
●Engine: Return to the original
trouble condition
●Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
●Harness and connectors
●Engine coolant temperature sen-
sor
●Fuel injectors
FUEL PUMP
RELAY
●Ignition switch: ON (Engine
stopped)
●Turn the fuel pump relay “ON”
and “OFF” using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.●Harness and connectors
●Fuel pump relay
PURG VOL
CONT/V
●Engine: After warming up, run
engine at 1,500 rpm.
●Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.E ngi ne s p eed c hange s ac c o rd in g to
the opening percent.●Harness and connectors
●Solenoid valve
V/T ASSIGN
ANGLE
●Engine: Return to the original
trouble condition
●Change intake valve timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
●Harness and connectors
●Intake valve timing control sole-
noid valve TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
Test mode Test item Condition Reference page
HO2S1HO2S1 (B1) P0133
Refer to corresponding
trouble diagnosis for
DTC.EC-905
HO2S1 (B1) P0134EC-914
HO2S1 (B1) P1143EC-1023
HO2S1 (B1) P1144EC-1029
HO2S2HO2S2 (B1) P0139EC-927HO2S2 (B1) P1146EC-1035
HO2S2 (B1) P1147EC-1042

DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
EC-949
[QR20(WITH EURO-OBD)]
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EC
5.CHECK IGNITION SPARK
1. Disconnect ignition coil assembly from rocker cover.
2. Connect a known-good spark plug to the ignition coil assembly.
3. Place end of spark plug against a suitable ground and crank engine.
4. Check for spark.
OK or NG
OK >> GO TO 6.
NG >> Check ignition coil, power transistor and their circuits.
Refer to EC-1074, "
IGNITION SIGNAL" .
6.CHECK SPARK PLUGS
Remove the spark plugs and check for fouling, etc.
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-24, "
Checking
and Changing Spark Plugs" .
7.CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-59, "
CHECKING COMPRESSION PRESSURE" .
OK or NG
OK >> GO TO 8.
NG >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
8.CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to EC-775, "
FUEL PRESSURE RELEASE" .
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-775, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 9.
NG >> Follow the Instruction of “FUEL PRESSURE CHECK”.
SEF575Q
SEF156I
Standard:
1,190 kPa (11.9 bar, 12.1 kg/cm2 , 172 psi)/250
rpm
Minimum:
990 kPa (9.9 bar, 10.1 kg/cm
2 , 144 psi)/250 rpm
Difference between each
cylinder:98 kPa (0.98 bar, 1.0 kg/cm
2 , 14 psi)/250 rpm
At idle: Approx. 350 kPa (3.5 bar, 3.57 kg/cm
2 , 51 psi)