2001 NISSAN X-TRAIL OBD port

EC-196
[QR25(WITH EURO-OBD)]
DTC P0139 HO2S2
Diagnostic Procedure
EBS00M4J
1. RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 2.
2. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode
with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0172 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF”.
3. Disconnect mass air flow sensor harness connector, and 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. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-1142, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0172 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171 or P0172. Refer to EC-200 or EC-206 .
No >> GO TO 3.
PBIB0494E
SEF215Z
PBIB0495E

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

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 P0420 THREE WAY CATALYST FUNCTION
EC-239
[QR25(WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC
DTC P0420 THREE WAY CATALYST FUNCTIONPFP:20905
On Board Diagnosis LogicEBS00M5U
The ECM monitors the switching frequency ratio of heated oxygen
sensors 1 and 2.
A three way catalyst (Manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decreases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2
approaches a specified limit value, the three way catalyst (Manifold)
malfunction is diagnosed.
DTC Confirmation ProcedureEBS00M5V
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
TESTING CONDITION:
●Open engine hood before conducting the following procedure.
●Do not hold engine speed for more than the specified minutes below.
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch ″OFF″ and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least one minute under no
load.
4. Let engine idle for one minute.
5. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUP-
PORT” mode with CONSULT-II.
6. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecu-
tive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “COMPLT”, go to step 9
7. Wait 5 seconds at idle.
SEF484YF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420Catalyst system effi-
ciency below threshold
●Three way catalyst (Manifold) does not oper-
ate properly.
●Three way catalyst (Manifold) does not have
enough oxygen storage capacity.
●Three way catalyst (Manifold)
●Exhaust tube
●Intake air leaks
●Fuel injectors
●Fuel injector leaks
●Spark plug
●Improper ignition timing
PBIB0822E

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-298
[QR25(WITH EURO-OBD)]
DTC P1143 HO2S1
2. RETIGHTEN HEATED OXYGEN SENSOR 1
Loosen and retighten heated oxygen sensor 1.
>> GO TO 3.
3. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF”.
3. Disconnect mass air flow sensor harness connector, and 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. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-56, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171. Refer to EC-200 .
No >> GO TO 4.
4. CHECK HEATED OXYGEN SENSOR 1 HEATER
Refer to EC-132, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace heated oxygen sensor 1.Tightening torque: 40 - 50 N·m (4.1 - 5.1 kg-m, 30 - 37 ft-lb)
PBIB0499E
SEF215Z
PBIB0495E

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

EC-304
[QR25(WITH EURO-OBD)]
DTC P1144 HO2S1
2. RETIGHTEN HEATED OXYGEN SENSOR 1
Loosen and retighten heated oxygen sensor 1.
>> GO TO 3.
3. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF”.
3. Disconnect mass air flow sensor harness connector, and 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. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-56, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0172. Refer to EC-206 .
No >> GO TO 4.Tightening torque: 40 - 50 N·m (4.1 - 5.1 kg-m, 30 - 37 ft-lb)
PBIB0499E
SEF215Z
PBIB0495E