2003 NISSAN ALMERA N16 ecm

EC-304
[QG (WITH EURO-OBD)]
DTC P1144 HO2S1
Overall Function Check
EBS00KAQ
Use this procedure to check the overall function of the heated oxygen sensor 1 circuit. During this check, a
DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM terminal 35 (HO2S1 signal) and engine ground.
3. Check one of the following with engine speed held at 2,000 rpm
constant under no load.
–The maximum voltage is below 0.8V at least one time.
–The minimum voltage is below 0.35V at least one time.
4. If NG, go to EC-304, "
Diagnostic Procedure" .
Diagnostic ProcedureEBS00KAR
1. RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 2.
2. RETIGHTEN HEATED OXYGEN SENSOR 1
Loosen and retighten heated oxygen sensor 1.
>> GO TO 3.
MBIB0018E
MBIB0095E
Tightening torque: 40 - 60 N·m (4.1 - 6.2 kg-m, 30 - 44 ft-lb)
MBIB0098E

DTC P1144 HO2S1
EC-307
[QG (WITH EURO-OBD)]
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●Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM terminal 35 (HO2S1 signal) and engine ground.
3. Check the following with engine speed held at 2,000 rpm con-
stant under no load.
●The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V
more than 5 times within 10 seconds.
●The maximum voltage is over 0.6V at least one time.
●The minimum voltage is below 0.3V at least one time.
●The voltage never exceeds 1.0V.
1 time: 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V
2 times: 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V → 0.6 - 1.0V
CAUTION:
●Discard any heated oxygen sensor which has been dropped
from a height 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 oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and InstallationEBS00KAT
HEATED OXYGEN SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND CATALYTIC CONVERTER" .
MBIB0018E

EC-308
[QG (WITH EURO-OBD)]
DTC P1146 HO2S2
DTC P1146 HO2S2
PFP:226A0
Component DescriptionEBS00KAU
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor ModeEBS00KAV
Specification data are reference values.
On Board Diagnosis LogicEBS00KAW
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxygen
storage capacity before the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the minimum voltage of sensor is
sufficiently low during the various driving condition such as fuel-cut.
DTC Confirmation ProcedureEBS00KAX
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
●“COMPLETED” will appear on CONSULT-II screen when all tests “COND1”, “COND2” and
“COND3” are completed.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
●Engine: After warming up
●Keeping the engine speed
between 3,500 and 4,000 rpm
for one minute and at idle for
one minute under no loadRevving engine from idle to 3,000
rpm quickly.0 - 0.3V ←→ Approx. 0.6 - 1.0V
HO2S2 MNTR (B1)
●Engine: After warming up
●Keeping the engine speed
between 3,500 and 4,000 rpm
for one minute and at idle for
one minute under no loadRevving engine from idle to 3,000
rpm quickly.LEAN ←→ RICH
SEF258VA
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1146
1146Heated oxygen sensor 2
minimum voltage monitoringThe minimum voltage from the sensor is not
reached to the specified voltage.
●Harness or connectors
(The sensor circuit is open or shorted.)
●Heated oxygen sensor 2
●Fuel pressure
●Injectors

EC-310
[QG (WITH EURO-OBD)]
DTC P1146 HO2S2
Procedure for COND3
1. Stop vehicle and let it idle until “INCOMPLETE” of “COND3” on
CONSULT-II screen has turned to “COMPLETED”. (It will take a
maximum of approximately 6 minutes.)
2. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULTS”.
If “NG” is displayed, refer to EC-312, "
Diagnostic Procedure" .
If “CAN NOT BE DIAGNOSED” is displayed, perform the follow-
ing.
a. Turn ignition switch “OFF” and leave the vehicle in a cool place
(soak the vehicle).
b. Turn ignition switch “ON” and select “COOLANTEMP/S” in
“DATA MONITOR” mode with CONSULT-II
c. Start engine and warm it up while monitoring “COOLANTEMP/S” indication on CONSULT-II.
d. When ″COOLANTEMP/S″ indication reaches to 70°C (158°F), go to ″Procedure for COND 1″ step 3.
Overall Function CheckEBS00KAY
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a
DTC might not be confirmed.
WITH GST
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 one minute.
5. Set voltmeter probes between ECM terminal 16 (HO2S2 signal) and engine ground.
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be below 0.56V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in “D”
position with “OD” OFF (A/T), 3rd gear position (M/T).
The voltage should be below 0.56V at least once during this
procedure.
8. If NG, go to EC-312, "
Diagnostic Procedure" .
SEC775C
MBIB0020E

EC-312
[QG (WITH EURO-OBD)]
DTC P1146 HO2S2
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureEBS00KB0
1. RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 2.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
16 W Heated oxygen sensor 2[Engine is running]
●Warm-up condition
●Engine speed is 3,000 rpm after the following
conditions are met.
●Keeping the engine speed between 3,500 and
4,000 rpm for one minute and at idle for one
minute under no load0 - Approximately 1.0V
74 BHeated oxygen sensor
ground[Engine is running]
●Idle speedApproximately 0V
MBIB0095E

DTC P1146 HO2S2
EC-313
[QG (WITH EURO-OBD)]
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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 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 that DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-48, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure that 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-193 .
No >> GO TO 3.
3.CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 74 and HO2S2
terminal 3.
Refer to Wiring Diagram.
5. 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.
SEF215Z
MBIB0096E
Continuity should exist.
MBIB0256E

EC-314
[QG (WITH EURO-OBD)]
DTC P1146 HO2S2
4. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 16 and HO2S2 terminal 2.
Refer to Wiring Diagram.
2. Check harness continuity between ECM terminal 16 or HO2S2 terminal 2 and ground.
Refer to Wiring Diagram.
3. Also check harness for 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 HEATED OXYGEN SENSOR 2
Refer to EC-314, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-109, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS00KB1
HEATED OXYGEN SENSOR 2
With CONSULT-II
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 and wait until 2 minutes have passed from starting the engine.
5. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)” as the monitor item with CONSULT-II.Continuity should exist.
Continuity should not exist.
SEF662Y

DTC P1146 HO2S2
EC-315
[QG (WITH EURO-OBD)]
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6. Check “HO2S2 (B1)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)” should be above 0.68V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)” should be below 0.56V at least once when the “FUEL INJECTION” is −25%.
CAUTION:
●Discard any heated oxygen sensor which has been dropped from a height 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 oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Without CONSULT-II
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. Set voltmeter probes between ECM terminal 16 (HO2S2 signal) and engine ground.
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.68V at least once during this
procedure.
If the voltage is above 0.68V at step 6, step 7 is not neces-
sary.
7. Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in “D”
position with “OD” OFF (A/T) 3rd gear position (M/T).
The voltage should be below 0.56V at least once during this
procedure.
8. If NG, replace heated oxygen sensor 2.
CAUTION:
●Discard any heated oxygen sensor which has been dropped from a height 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 oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and InstallationEBS00KB2
HEATED OXYGEN SENSOR 2
Refer to FE-10.
SEF244YA
MBIB0020E