2001 NISSAN X-TRAIL check engine

DTC P0171 FUEL INJECTION SYSTEM FUNCTION
EC-205
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7.CHECK INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch “OFF”.
3. Disconnect injector harness connectors.
4. Remove injector gallery assembly. Refer to EM-32
.
Keep fuel hose and all injectors connected to injector gallery.
The injector harness connectors should remain connected.
5. Disconnect all ignition coil harness connectors.
6. Prepare pans or saucers under each injector.
7. Crank engine for about 3 seconds. Make sure that fuel sprays
out from injectors.
OK or NG
OK >> GO TO 8.
NG >> Replace injectors from which fuel does not spray out.
Always replace O-ring with new ones.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-115, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Fuel should be sprayed evenly for each injector.
SEF595Q

EC-206
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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-207
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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-
209, "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-209, "
Diagnostic Procedure" . If engine does not start, check exhaust and intake
air leak visually.
PBIB0495E

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
EC-209
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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)

EC-210
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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-138, "
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-388
. 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-211
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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-115, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END

DTC P0222, P0223 TP SENSOR
EC-215
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Diagnostic ProcedureEBS00MPK
1.RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 2.
2.CHECK THROTTLE POSITION SENSOR POWER SUPPLY CIRCUIT
1. Disconnect electric throttle control actuator harness connector.
2. Turn ignition switch “ON”.
3. Check voltage between electric throttle control actuator terminal
1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3.CHECK THROTTLE POSITION SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Check harness continuity between electric throttle control actuator terminal 5 and engine ground.
Refer to Wiring Diagram.
3. Also check harness for short to ground and 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.
PBIB0925E
PBIB0497E
Voltage: Approximately 5V
PBIB0082E
Continuity should exist.

EC-216
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DTC P0222, P0223 TP SENSOR
4. CHECK THROTTLE POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 73 and electric throttle control actuator terminal 4.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK THROTTLE POSITION SENSOR
Refer to EC-216, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-39, "
Throttle Valve Closed Position Learning" .
3. Perform EC-39, "
Idle Air Volume Learning" .
>>INSPECTION END
7. CHECK INTERMITTENT INCIDENT
Refer to EC-115, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS00MPL
THROTTLE POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Perform EC-39, "
Throttle Valve Closed Position Learning" .
3. Turn ignition switch “ON”.
4. Set selector lever to “D” position (A/T models) or “1st” position (M/T models).
5. Check voltage between ECM terminals 73 (TP sensor 1), 74 (TP
sensor 2) and engine ground under the following conditions.
6. If NG, replace electric throttle control actuator and go to the next
step.
7. Perform EC-39, "
Throttle Valve Closed Position Learning" .
8. Perform EC-39, "
Idle Air Volume Learning" .
Remove and InstallationEBS00MPM
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-16, "INTAKE MANIFOLD" . Continuity should exist.
Terminal Accelerator pedal Voltage
73
(Throttle position sensor 1)Fully released More than 0.36V
Fully depressed Less than 4.75V
74
(Throttle position sensor 2)Fully released Less than 4.75V
Fully depressed More than 0.36V
PBIB0559E