2003 NISSAN ALMERA N16 ecm

EC-636
[QG (WITHOUT EURO-OBD)]
HO2S1 HEATER
2. CHECK HO2S1 POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect heated oxygen sensor 1 harness connector.
3. Turn ignition switch “ON”.
4. Check voltage between HO2S1 terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
●Harness connectors M182, E251
●Harness connectors E75, F36
●Fuse block (J/B) connector M1
●10A fuse
●Harness for open or short between heated oxygen sensor 1 and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK HO2S1 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 24 and HO2S1 terminal 1.
Refer to Wiring Diagram.
4. 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.
MBIB0091E
Voltage: Battery voltage
PBIB0541E
Continuity should exist.

EC-638
[QG (WITHOUT EURO-OBD)]
HO2S2 HEATER
HO2S2 HEATER
PFP:226A0
DescriptionEBS00KKG
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeEBS00KKH
Specification data are reference values.
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater Crankshaft position sensor (POS)
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,800 OFF
●Below 3,800 rpm after the following conditions are met.
●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 loadON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
●Engine speed: Below 3,800 rpm after the following conditions are met.
●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 loadON
●Engine speed: Above 3,800 rpm OFF

EC-640
[QG (WITHOUT EURO-OBD)]
HO2S2 HEATER
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 ProcedureEBS00KKJ
1. CHECK OVERALL FUNCTION CHECK
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 the voltmeter probe between ECM terminal 2 (HO2S2 heater signal) and ground.
6. Check the voltage under the following conditions.
OK or NG
OK >>INSPECTION END.
NG >> GO TO 2.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
2R/BHeated oxygen sensor 2
heater[Engine is running]
●Engine speed: Below 3,800 rpm [after the fol-
lowing conditions are met.]
●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 load.0 - 1.0V
[Ignition switch “ON”]
●Engine stopped
[Engine is running]
●Engine speed is above 3,800 rpm.BATTERY VOLTAGE
(11 - 14V)
Conditions Voltage
At idle 0 - 1V
Engine speed is above 3,600 rpm Battery voltage
PBIB0673E

HO2S2 HEATER
EC-641
[QG (WITHOUT EURO-OBD)]
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2.CHECK HO2S2 POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Turn ignition switch “ON”.
4. Check voltage between HO2S2 terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
●Harness connectors M182, E251
●Harness connectors E75, F36
●Fuse block (J/B) connector M1
●10A fuse
●Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 2 and HO2S2 terminal 1.
Refer to Wiring Diagram.
4. 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.
MBIB0256E
Voltage: Battery voltage
PBIB0541E
Continuity should exist.

IAT SENSOR
EC-643
[QG (WITHOUT EURO-OBD)]
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EC
IAT SENSORPFP:22630
Component DescriptionEBS00KKM
The intake air temperature sensor is built into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.

*: These data are reference values and are measured between ECM terminal 34
(Intake air temperature sensor) and body ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
SEC266C
Intake air
temperature°C (°F)Voltage* V Resistance kΩ
25 (77) 3.32 1.9 - 2.1
80 (176) 1.23 0.31 - 0.37
SEF012P

IAT SENSOR
EC-645
[QG (WITHOUT EURO-OBD)]
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Diagnostic ProcedureEBS00KKO
1.CHECK OVERALL FUNCTION
1. Turn ignition switch “ON”.
2. Check voltage between ECM terminal 34 and ground with CON-
SULT-II or tester.
OK or NG
OK >>INSPECTION END.
NG >> GO TO 2.
2.CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect mass air flow sensor (intake air temperature sensor
is built-into) harness connector.
3. Turn ignition switch “ON”.
4. Check voltage between MAF sensor terminal 5 and ground.
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 INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 67 and mass air flow sensor terminal 3.
Refer to Wiring Diagram.
4. 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. Voltage: Approximately 0 - 4.8V
MBIB0041E
MBIB0096E
Voltage: Approximately 5V
PBIB0066E
Continuity should exist.

HO2S1
EC-647
[QG (WITHOUT EURO-OBD)]
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HO2S1PFP:22690
Component DescriptionEBS00KKR
The heated oxygen sensor 1 is placed into the exhaust manifold. It
detects the amount of oxygen in the exhaust gas compared to the
outside air. The heated oxygen sensor 1 has a closed-end tube
made of ceramic zirconia. The zirconia generates voltage from
approximately 1V in richer conditions to 0V in leaner conditions. The
heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts
the injection pulse duration to achieve the ideal air-fuel ratio. The
ideal air-fuel ratio occurs near the radical change from 1V to 0V.
CONSULT-II Reference Value in Data Monitor ModeEBS00KKS
Specification data are reference values.
SEF463R
SEF288D
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 (B1)
●Engine: After warming up Maintaining engine speed at 2,000 rpm 0 - 0.3V ←→ Approx. 0.6 - 1.0V
HO2S1 MNTR (B1)
●Engine: After warming up Maintaining engine speed at 2,000 rpmLEAN←→ RICH
Changes more than 5 times dur-
ing 10 seconds.

HO2S1
EC-649
[QG (WITHOUT EURO-OBD)]
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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 ProcedureEBS00KKU
1.INSPECTION START
Do you have CONSULT-II?
Ye s o r N o
Ye s > > G O T O 2 .
No >> GO TO 3.
2.CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “HO2S1 MNTR (B1)” in “DATA MONITOR” mode with CONSULT-II.
3. Keep the engine speed at 2,000 rpm under no load, and make
sure that the monitors fluctuate between LEAN and RICH more
than five times in 10 seconds.
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
3.CHECK OVERALL FUNCTION
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. Keep the engine speed at 2,000 rpm under no load, and make
sure that the voltage fluctuates between 0 to 0.3V and 0.6 to
1.0V more than five times in 10 seconds.
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
35 W Heated oxygen sensor 1[Engine is running]
●Warm-up condition
●Engine speed is 2,000 rpm.0 - Approximately 1.0V
(Periodically change)
74 BHeated oxygen sensor
ground[Engine is running]
●Idle speedApproximately 0V
1 time: RICH → LEAN → RICH
2 times: RICH → LEAN → RICH → LEAN → RICH
SEF646Y
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 → 0 - 0.3V
MBIB0018E