NISSAN X-TRAIL 2001 Service Repair Manual

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
EC-941
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3. Disconnect mass air flow sensor harness connector. Then
restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Select “MODE 3” with GST. Make sure DTC P0102 is detected.
6. Select “MODE 4” with GST and erase the DTC P0102.
7. Start engine again and let it idle for at least 10 minutes.
8. Select “MODE 7” with GST. The 1st trip DTC P0172 should be
detected at this stage, if a malfunction exists. If so, go to EC-
943, "Diagnostic Procedure" .
9. If it is difficult to start engine at step 7, the fuel injection system
has a malfunction.
10. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-943, "
Diagnostic Procedure" . If engine does not start, check exhaust and intake
air leak visually.
PBIB0495E

EC-942
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DTC P0172 FUEL INJECTION SYSTEM FUNCTION
Wiring Diagram
EBS00MWV
TBWA0063E

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
EC-943
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Diagnostic ProcedureEBS00MWW
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-775, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-775, "
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)

EC-944
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DTC P0172 FUEL INJECTION SYSTEM FUNCTION
5. CHECK MASS AIR FLOW SENSOR
With CONSULT-II
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-II.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in MODE 1 with GST.
OK or NG
OK >> GO TO 6.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
engine grounds. Refer to EC-870, "
DTC P0102, P0103 MAF SENSOR" .
6. CHECK FUNCTION OF INJECTORS
With CONSULT-II
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
OK or NG
OK >> GO TO 7.
NG >> Perform trouble diagnosis for “INJECTORS”, EC-1083
. 1.0 - 4.0 g·m/sec: at idling
4.0 - 10 g·m/sec: at 2,500 rpm
1.0 - 4.0 g·m/sec: at idling
4.0 - 10 g·m/sec: at 2,500 rpm
PBIB0133E
Clicking noise should be heard.
MEC703B

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
EC-945
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7.CHECK INJECTOR
1. Remove injector assembly. Refer to EM-32, "
FUEL INJECTOR AND FUEL TUBE" .
Keep fuel hose and all injectors connected to injector gallery.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect injector harness connectors.
The injector harness connectors should remain connected.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each injectors.
6. Crank engine for about 3 seconds.
Make sure fuel does not drip from injector.
OK or NG
OK (Does not drip.)>>GO TO 8.
NG (Drips.)>>Replace the injectors from which fuel is dripping. Always replace O-ring with new one.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-847, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END

EC-946
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DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
PFP:00000
On Board Diagnosis LogicEBS00MWX
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 ProcedureEBS00MWY
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.

DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
EC-947
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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 condi-
tions.
5. If 1st trip DTC is detected, go to EC-947, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureEBS00MWZ
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 catalysts and muffler for dents.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace it.
PBIB0164E

EC-948
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DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
3. PERFORM POWER BALANCE TEST
With CONSULT-II
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Is there any cylinder which does not produce a momentary
engine speed drop?
Without CONSULT-II
When disconnecting each injector harness connector one at a time,
is there any cylinder which does not produce a momentary engine
speed drop?
Ye s o r N o
Yes >> GO TO 4.
No >> GO TO 7.
4. CHECK INJECTOR
Does each injector make an operating sound at idle?
Ye s o r N o
Yes >> GO TO 5.
No >> Check injector(s) and circuit(s). Refer to EC-1083,
"INJECTOR CIRCUIT" .
PBIB0133E
PBIB0510E
MEC703B

DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
EC-949
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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)

EC-950
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DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
9. CHECK IGNITION TIMING
Check the following items. Refer to EC-805, "
Basic Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Follow the “Basic Inspection”.
10. CHECK HEATED OXYGEN SENSOR 1
Refer to EC-903, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 . CHECK MASS AIR FLOW SENSOR
With CONSULT-II
Check mass air flow sensor signal in “DATA MONITOR” mode with CONSULT-II.
With GST
Check mass air flow sensor signal in MODE 1 with GST.
OK or NG
OK >> GO TO 12.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
engine grounds. Refer to EC-870, "
DTC P0102, P0103 MAF SENSOR" .
12. CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in EC-809, "
Symptom Matrix Chart" .
OK or NG
OK >> GO TO 13.
NG >> Repair or replace.
13. ERASE THE 1ST TRIP DTC
Some tests may cause a 1st trip DTC to be set.
Erase the 1st trip DTC from the ECM memory after performing the tests. Refer to EC-788, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
>> GO TO 14.
14. CHECK INTERMITTENT INCIDENT
Refer to EC-847, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Items Specifications
Target idle speedA/T 700 ± 50 rpm (in “P” or “N” position)
M/T 650 ± 50 rpm
Ignition timingA/T 16 ± 5° BTDC (in “P” or “N” position)
M/T 14 ± 5° BTDC
1.4 - 4.0 g·m/sec: at idling
4.0 - 10.0 g·m/sec: at 2,500 rpm
1.4 - 4.0 g·m/sec: at idling
4.0 - 10.0 g·m/sec: at 2,500 rpm