2001 NISSAN X-TRAIL fuel pressure

EC-200
[QR25(WITH EURO-OBD)]
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
PFP:16600
On Board Diagnosis LogicEBS00M4M
With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensor 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and light up the MI (2 trip detection logic).
DTC Confirmation ProcedureEBS00M4N
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Turn ignition switch “ON” and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0171 should be detected at this stage, if a
malfunction exists. If so, go to EC-203, "
Diagnostic Procedure" .
7. If it is difficult to start engine at step 6, the fuel injection system
has a malfunction, too.
8. Crank engine while depressing accelerator pedal. If engine
starts, go to EC-203, "
Diagnostic Procedure" . If engine does not
start, check exhaust and intake air leak visually.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
Sensor Input Signal to ECMECM
functionActuator
Heated oxygen sensors 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion controlFuel injectors
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0171
0171Fuel injection system
too lean
●Fuel injection system does not operate properly.
●The amount of mixture ratio compensation is too
large.
(The mixture ratio is too lean.)
●Intake air leaks
●Heated oxygen sensor 1
●Injectors
●Exhaust gas leaks
●Incorrect fuel pressure
●Lack of fuel
●Mass air flow sensor
●Incorrect PCV hose connection
SEF215Z

DTC P0171 FUEL INJECTION SYSTEM FUNCTION
EC-203
[QR25(WITH EURO-OBD)]
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Diagnostic ProcedureEBS00M4P
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK FOR INTAKE AIR LEAK AND PCV HOSE
1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK HEATED OXYGEN SENSOR 1 CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect corresponding heated oxygen sensor 1 (HO2S1) harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 92 and HO2S1 terminal 2.
Refer to Wiring Diagram.
5. Check harness continuity between ECM terminal 92 or HO2S1 terminal 2 and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-42, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-42, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 5.
NG >> Follow the instruction of “FUEL PRESSURE CHECK”.
SEC502D
Continuity should exist.
Continuity should not exist.
At idling: Approximately 350 kPa (3.5 bar, 3.57 kg/cm
2 , 51 psi)

EC-206
[QR25(WITH EURO-OBD)]
DTC P0172 FUEL INJECTION SYSTEM FUNCTION
DTC P0172 FUEL INJECTION SYSTEM FUNCTION
PFP:16600
On Board Diagnosis LogicEBS00M4Q
With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and light up the MI (2 trip detection logic).
DTC Confirmation ProcedureEBS00M4R
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Turn ignition switch “ON” and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0172 should be detected at this stage, if a
malfunction exists. If so, go to EC-209, "
Diagnostic Procedure" .
7. If it is difficult to start engine at step 6, the fuel injection system
has a malfunction, too.
8. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-209, "
Diagnostic Procedure" . If engine
does not start, remove ignition plugs and check for fouling, etc.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
Sensor Input Signal to ECMECM
functionActuator
Heated oxygen sensors 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion controlFuel injectors
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0172
0172Fuel injection system
too rich
●Fuel injection system does not operate properly.
●The amount of mixture ratio compensation is too
large.
(The mixture ratio is too rich.)
●Heated oxygen sensor 1
●Injectors
●Exhaust gas leaks
●Incorrect fuel pressure
●Mass air flow sensor
SEF215Z

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
EC-209
[QR25(WITH EURO-OBD)]
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Diagnostic ProcedureEBS00M4T
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK HEATED OXYGEN SENSOR 1 CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect corresponding heated oxygen sensor 1 (HO2S1) harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 92 and HO2S1 terminal 2.
Refer to Wiring Diagram.
5. Check harness continuity between ECM terminal 92 or HO2S1 terminal 2 and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-42, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-42, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 5.
NG >> Follow the Instruction of “FUEL PRESSURE CHECK”.
SEC502D
Continuity should exist.
Continuity should not exist.
At idling: 350 kPa (3.5 bar, 3.57 kg/cm2, 51 psi)

DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
EC-217
[QR25(WITH EURO-OBD)]
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EC
DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
PFP:00000
On Board Diagnosis LogicEBS00M52
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary, ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the first trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to over-
heating, the MI will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor (POS) signal every 200 engine revo-
lutions for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MI will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MI will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MI will remain on.
If another misfire condition occurs that can damage the TWC, the MI will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MI will only light
when the misfire is detected on a second trip. During this condition, the ECM monitors the CKP sensor
signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC Confirmation ProcedureEBS00M53
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch “ON”, and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch “OFF” and wait at least 10 seconds.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300
0300Multiple cylinder misfire
detectedMultiple cylinder misfire.
●Improper spark plug
●Insufficient compression
●Incorrect fuel pressure
●The injector circuit is open or shorted
●Fuel injectors
●Intake air leak
●The ignition signal circuit is open or
shorted
●Lack of fuel
●Drive plate or flywheel
●Heated oxygen sensor 1 P0301
0301No.1 cylinder misfire
detectedNo. 1 cylinder misfires.
P0302
0302No. 2 cylinder misfire
detectedNo. 2 cylinder misfires.
P0303
0303No. 3 cylinder misfire
detectedNo. 3 cylinder misfires.
P0304
0304No. 4 cylinder misfire
detectedNo. 4 cylinder misfires.

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-296
[QR25(WITH EURO-OBD)]
DTC P1143 HO2S1
On Board Diagnosis Logic
EBS00M80
To judge the malfunction, the output from the heated oxygen sensor
1 is monitored to determine whether the “rich” output is sufficiently
high and whether the “lean” output is sufficiently low. When both the
outputs are shifting to the lean side, the malfunction will be detected.
DTC Confirmation ProcedureEBS00M81
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
●Always perform at a temperature above −10°C (14°F).
●Before performing following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine and wait at least 10 seconds.
3. Turn ignition switch “ON” and select “HO2S1 (B1) P1143” of “HO2S1” in “DTC WORK SUPPORT” mode
with CONSULT-II.
4. Touch “START”.
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.
SEF300U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1143
11 4 3Heated oxygen sensor
1 lean shift monitoringThe maximum and minimum voltage from the
sensor are not reached to the specified volt-
ages.
●Heated oxygen sensor 1
●Heated oxygen sensor 1 heater
●Fuel pressure
●Injectors
●Intake air leaks
PBIB0546E

EC-302
[QR25(WITH EURO-OBD)]
DTC P1144 HO2S1
On Board Diagnosis Logic
EBS00M89
To judge the malfunction, the output from the heated oxygen sensor
1 is monitored to determine whether the “rich” output is sufficiently
high. The “lean” output is sufficiently low. When both the outputs are
shifting to the rich side, the malfunction will be detected.
DTC Confirmation ProcedureEBS00M8A
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
●Always perform at a temperature above −10°C (14°F).
●Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine and wait at least 5 seconds.
3. Turn ignition switch “ON” and select “HO2S1 (B1) P1144” of “HO2S1” in “DTC WORK SUPPORT” mode
with CONSULT-II.
4. Touch “START”.
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.
SEF299U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1144
11 4 4Heated oxygen sensor
1 rich shift monitoringThe maximum and minimum voltages from the
sensor are beyond the specified voltages.
●Heated oxygen sensor 1
●Heated oxygen sensor 1 heater
●Fuel pressure
●Injectors
PBIB0548E