NISSAN LATIO 2009 Service Repair Manual

P0138 HO2S2
EC-215
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Wiring Diagram
INFOID:0000000004780713
Diagnosis Procedure INFOID:00000000047801281.
INSPECTION START
Confirm the detected malfunction (A or B). Refer to EC-212, " DTC Logic " .
Which malfunction is detected? BBWA2629E

Ground Inspection " .
Is the inspection result normal? YES >> GO TO 3.
NO >> Repair or replace ground connection. YES >> GO TO 4.
NO >> Repair or replace harness or connectors. YES >> GO TO 5.
NO >> Repair open circuit or short to ground or short to power in harness or connectors. YES >> GO TO 6.
NO >> Repair open circuit or short to ground or short to power in harness or connectors. HO2S2 ECM
Continuity
Connector Terminal Connector Terminal
F13 4 F11 50 Existed
HO2S2 Ground Continuity
Connector Terminal
F13 4 Ground Not existed
ECM Ground Continuity
Connector Terminal
F11 50 Ground Not existed

EC
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Refer to
EC-218, " Component Inspection " .
Is the inspection result normal? YES >> GO TO 8.
NO >> GO TO 7. Diagnosis Procedure " .
>> INSPECTION END Ground Inspection " .
Is the inspection result normal? YES >> GO TO 10.
NO >> Repair or replace ground connection. MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement " .
2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected? Is it difficult to start engine? YES >> Perform trouble diagnosis for DTC P0172. Refer to
EC-235, " DTC Logic " .
NO >> GO TO 11. YES >> GO TO 12.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.

YES >> GO TO 13.
NO >> Repair open circuit or short to ground or short to power in harness or connectors. Component Inspection " .
Is the inspection result normal? YES >> GO TO 15.
NO >> GO TO 14. Diagnosis Procedure " .
>> INSPECTION END
Component Inspection INFOID:0000000004780129YES >> GO TO 2.
NO >> GO TO 3.

P0138 HO2S2
EC-219
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5. Let engine idle for 1 minute.
6. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select “HO2S2 (B1)” as the monitor item with
CONSULT-III.
7. Check “HO2S2 (B1)” at idle speed when adjusting “FUEL INJECTION” to ± 25%.
“HO2S2 (B1)” should be above 0.68 V at least once when the “FUEL INJECTION” is + 25%.
“HO2S2 (B1)” should be below 0.18 V at l east once when the “FUEL INJECTION” is − 25%.
Is the inspection result normal? YES >> INSPECTION END
NO >> GO TO 6. 3.
CHECK HEATED OXYGEN SENSOR 2-I
Without CONSULT-III
1. Start engine and warm it up to 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 1 minute under no load.
4. Let engine idle for 1 minute.
5. Check the voltage between ECM harness connector and ground under the following condition.
Is the inspection result normal? YES >> INSPECTION END
NO >> GO TO 4. 4.
CHECK HEATED OXYGEN SENSOR 2-II
Check the voltage between ECM harness connector and ground
under the following condition.
Is the inspection result normal? YES >> INSPECTION END
NO >> GO TO 5. PBIB3458E
ECM
Ground Condition Voltage
Con-
nector Termi-
nal
F11 50
(HO2S2 signal) Ground Revving up to 4,000
rpm under no load at
least 10 times The voltage should be
above 0.68 V at least once
during this procedure.
The voltage should be be-
low 0.18 V at least once
during this procedure. PBIB2996E
ECM
Ground Condition Voltage
Con-
nector Termi-
nal
F11 50
(HO2S2 signal) Ground
Keeping engine speed
at idle for 10 minutes The voltage should be
above 0.68 V at least once
during this procedure.
The voltage should be be-
low 0.18 V at least once
during this procedure. JMBIA2199ZZ

EC-220< COMPONENT DIAGNOSIS >
[HR16DE]
P0138 HO2S2 5.
CHECK HEATED OXYGEN SENSOR 2-III
Check the voltage between ECM harness connector and ground
under the following condition.
Is the inspection result normal? YES >> INSPECTION END
NO >> GO TO 6. 6.
REPLACE HEATED OXYGEN SENSOR 2
Replace heated oxygen sensor 2.
CAUTION:
• Discard any sensor which has been dropped from a he ight of more than 0.5 m (19.7 in) onto a hard
surface such as a concrete floor; use a new one.
• Before installing new sensor, clean exhaust system threads usi ng Oxygen Sensor Thread Cleaner
[commercial service tool (J-43897-18 or J43897-12)] and approved Anti-seize Lubricant (commercial
service tool).
>> INSPECTION END
ECM
Ground Condition Voltage
Con-
nector Termi-
nal
F11 50
(HO2S2
signal) Ground Coasting from 80 km/h
(50 MPH) in D position
(A/T), 4th gear position
(M/T) The voltage should be
above 0.68 V at least once
during this procedure.
The voltage should be be-
low 0.18 V at least once
during this procedure. JMBIA2200ZZ

P0139 HO2S2
EC-221
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P0139 HO2S2
Description INFOID:0000000004780130
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1 V in richer conditions to 0 V in leaner con-
ditions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
DTC Logic INFOID:0000000004780131
DTC DETECTION LOGIC The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the switching response of the sen-
sor's voltage is faster than specified during the various driving condi-
tion such as fuel-cut.
DTC CONFIRMATION PROCEDURE 1.
INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III? YES >> GO TO 2.
NO >> GO TO 5. 2.
PRECONDITIONING
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 3. 3.
PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to normal operating temperature. SEF327R
SEF302U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0139 Heated oxygen sensor 2
circuit slow response It takes more time for the sensor to respond
between rich and lean than the specified
time. • Harness or connectors
(The sensor circuit is open or shorted)
• Heated oxygen sensor 2
• Fuel pressure
• Fuel injector
• Intake air leaks

EC-222< COMPONENT DIAGNOSIS >
[HR16DE]
P0139 HO2S2
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Open engine hood.
6. Select “HO2S2 (B1) P0139” of “HO2S2” in “DTC WORK SUPPORT” mode with CONSULT-III.
7. Follow the instruction of CONSULT-III. NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
8. Touch “SELF-DIAG RESULT”.
Which is displayed on CONSULT-III? OK >> INSPECTION END
NG >> GO TO 4.
CAN NOT BE DIAGNOSED>>GO TO 4. 4.
PERFORM THE RESULT OF DTC CONFIRMATION PROCEDURE
1. Turn ignition switch OFF and leave the vehi cle in a cool place (soak the vehicle).
2. Perform DTC CONFIRMATION PROCEDURE again.
>> GO TO 3. 5.
PERFORM COMPONENT FUNCTION CHECK
Perform component function check. Refer to EC-222, " Component Function Check " .
NOTE:
Use component function check to check the overall func tion of the heated oxygen sensor 2 circuit. During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal? YES >> INSPECTION END
NO >> Go to EC-224, " Diagnosis Procedure " .
Component Function Check INFOID:00000000047801321.
PERFORM COMPONENT FUNCTION CHECK-I
Without CONSULT-III
1. Start engine and warm it up to 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 1 minute under no load.
4. Let engine idle for 1 minute.
5. Check the voltage between ECM harness connector and ground under the following condition.
Is the inspection result normal? YES >> INSPECTION END
NO >> GO TO 2. 2.
PERFORM COMPONENT FUNCTION CHECK-IIECM
Ground Condition Voltage
Con-
nector Terminal
F11 50
(HO2S2
signal) Ground
Revving up to 4,000
rpm under no load at
least 10 times The voltage should be above
0.30 V at least once during
this procedure. PBIB2996E

P0139 HO2S2
EC-223
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Check the voltage between ECM harness connector and ground
under the following condition.
Is the inspection result normal? YES >> INSPECTION END
NO >> GO TO 3. 3.
PERFORM COMPONENT FUNCTION CHECK-III
Check the voltage between ECM harness connector and ground
under the following condition.
Is the inspection result normal? YES >> INSPECTION END
NO >> Go to EC-224, " Diagnosis Procedure " .
ECM
Ground Condition Voltage
Con-
nector Terminal
F11 33
(HO2S2 signal) Ground
Keeping engine speed
at idle for 10 minutes The voltage should be
above 0.30 V at least once
during this procedure. JMBIA2199ZZ
ECM
Ground Condition Voltage
Con-
nector Termi-
nal
F11 33
(HO2S2 signal) Ground Coasting from 80 km/h
(50 MPH) in D position
(A/T), 4th gear position
(M/T) The voltage should be
above 0.30 V at least once
during this procedure. JMBIA2200ZZ

EC-224< COMPONENT DIAGNOSIS >
[HR16DE]
P0139 HO2S2
Wiring Diagram INFOID:0000000004780714
Diagnosis Procedure INFOID:00000000047801331.
CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connections E15, E24. Refer to EC-125, " Ground Inspection " .
Is the inspection result normal? BBWA2629E