2003 NISSAN ALMERA N16 ecm

EC-132
[QG (WITH EURO-OBD)]
DTC P0037, P0038 HO2S2 HEATER
2. 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.
3. 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 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK HEATED OXYGEN SENSOR 2 HEATER
Refer to EC-133, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace heated oxygen sensor 2.
5. CHECK INTERMITTENT INCIDENT
Refer to EC-109, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.

EC-134
[QG (WITH EURO-OBD)]
DTC P0102, P0103 MAF SENSOR
DTC P0102, P0103 MAF SENSOR
PFP:22680
Component DescriptionEBS00K4X
The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. It consists of a hot film that is supplied with electric current from
the ECM. The temperature of the hot film is controlled by the ECM a
certain amount. The heat generated by the hot film is reduced as the
intake air flows around it. The more air, the greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot film as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor ModeEBS00K4Y
Specification data are reference values.
On Board Diagnosis LogicEBS00K4Z
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
SEC266C
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1
●Engine: After warming up
●Air conditioner switch: OFF
●Shift lever:
N (A/T models)
Neutral (M/T models)
●No-loadIdle Approx. 1.0 - 1.7V
2,500 rpm Approx. 1.5 - 2.1V
CAL/LD VALUE
●Engine: After warming up
●Shift lever:
N (A/T models)
Neutral (M/T models)
●Air conditioner switch: OFF
●No-loadIdle 10% - 35%
2,500 rpm 10% - 35%
MASS AIRFLOW
●Engine: After warming up
●Shift lever:
N (A/T models)
Neutral (M/T models)
●Air conditioner switch: OFF
●No-loadIdle 1.0 - 4.0 g·m/s
2,500 rpm 5.0 - 10.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0102
0102Mass air flow sensor circuit
low inputAn excessively low voltage from the sensor
is sent to ECM when engine is running.
●Harness or connectors
(The sensor circuit is open or shorted.)
●Intake air leaks
●Mass air flow sensor
P0103
0103Mass air flow sensor circuit
high inputAn excessively high voltage from the sensor
is sent to ECM.
●Harness or connectors
(The sensor circuit is open or shorted.)
●Mass air flow sensor
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.

DTC P0102, P0103 MAF SENSOR
EC-137
[QG (WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC
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 ProcedureEBS00K52
1.INSPECTION START
Which malfunction (P0102 or P0103) is duplicated?
P0102 or P0103
P0102 >> GO TO 2.
P0103 >> GO TO 3.
2.CHECK INTAKE SYSTEM
Check the following for connection.
●Air duct
●Vacuum hoses
●Intake air passage between air duct to intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
3.RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 4.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
45 RSensor power supply
(Mass air flow sensor)[Ignition switch “ON”]Approximately 5V
50 Y Mass air flow sensor[Engine is running]
●Warm-up condition
●Idle speed1.0 - 1.7V
[Engine is running]
●Warm-up condition
●Engine speed is 2,500 rpm.1.5 - 2.1V
67 BSensor ground
(Mass air flow sensor)[Engine is running]
●Warm-up condition
●Idle speedApproximately 0V
MBIB0095E

EC-138
[QG (WITH EURO-OBD)]
DTC P0102, P0103 MAF SENSOR
4. CHECK MAF SENSOR POWER SUPPLY CIRCUIT
1. Disconnect MAF sensor harness connector.
2. Turn ignition switch “ON”.
3. Check voltage between MAF sensor terminals 2, 4 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
●Harness connectors E225, F43
●Harness for open or short between mass air flow sensor and ECM
●Harness for open or short between mass air flow sensor and ECM relay
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
MBIB0096E
Terminal Voltage
2 Approximately 5V
4 Battery voltage
PBIB0076E
Continuity should exist.

DTC P0102, P0103 MAF SENSOR
EC-139
[QG (WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC
7.CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 1 and ECM terminal 50.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK MASS AIR FLOW SENSOR
Refer to EC-139, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace mass air flow sensor.
9.CHECK INTERMITTENT INCIDENT
Refer to EC-109, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS00K53
MASS AIR FLOW SENSOR
1. Reconnect harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 50 (Mass air flow sensor
signal) and ground.
*: Check for liner voltage rise in response to engine being increased to about
4,000 rpm.
4. If the voltage is out of specification, proceed the following.
a. Turn ignition switch “OFF”.
b. Disconnect mass air flow sensor harness connector and reconnect it again.
c. Perform steps 2 and 3 again.
5. If NG, remove mass air flow sensor from air duct. Check hot film for damage or dust.
6. If NG, clean or replace mass air flow sensor.
Removal and InstallationEBS00K54
MASS AIR FLOW SENSOR
Refer to EM-14, "AIR CLEANER AND AIR DUCT" . Continuity should exist.
Condition Voltage V
Ignition switch “ON” (Engine stopped.) Approx. 1.0
Idle (Engine is warmed-up to normal operating
temperature.)1.0 - 1.7
2,500 rpm (Engine is warmed-up to normal
operating temperature.)1.5 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.7 to Approx. 4.0
MBIB0017E

EC-140
[QG (WITH EURO-OBD)]
DTC P0112, P0113 IAT SENSOR
DTC P0112, P0113 IAT SENSOR
PFP:22630
Component DescriptionEBS00K55
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 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 termi-
nals, such as the ground.
On Board Diagnosis LogicEBS00K56
DTC Confirmation ProcedureEBS00K57
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. Turn ignition switch “ON”.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-142, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEC266C
Intake air
temperature°C (°F)Vo lta g e * V R e s i s ta n c e kΩ
−10 (14) 4.43 7.9 - 9.3
25 (77) 3.32 1.9 - 2.1
80 (176) 1.23 0.31 - 0.37
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0112
0112Intake air temperature
sensor circuit low inputAn excessively low voltage from the sensor is
sent to ECM.
●Harness or connectors
(The sensor circuit is open or shorted.)
●Intake air temperature sensor P0113
0113Intake air temperature
sensor circuit high inputAn excessively high voltage from the sensor is
sent to ECM.
SEF058Y

EC-142
[QG (WITH EURO-OBD)]
DTC P0112, P0113 IAT SENSOR
Diagnostic Procedure
EBS00K59
1. 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 2.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
2. 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 MAF sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
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
Refer to EC-143, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
4. CHECK INTERMITTENT INCIDENT
Refer to EC-109, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
MBIB0096E
Voltage: Approximately 5V
PBIB0066E
Continuity should exist.

EC-144
[QG (WITH EURO-OBD)]
DTC P0117, P0118 ECT SENSOR
DTC P0117, P0118 ECT SENSOR
PFP:22630
Component DescriptionEBS00K5C
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

*: These data are reference values and are measured between ECM terminal 72
(Engine coolant temperature sensor) 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.
On Board Diagnosis LogicEBS00K5D
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When this malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
SEF594K
Engine coolant
temperature°C (°F)Voltage* V Resistance kΩ
−10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No. Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P0117
0117Engine coolant temperature
sensor circuit low inputAn excessively low voltage from the sensor is
sent to ECM.
●Harness or connectors
(The sensor circuit is open or shorted.)
●Engine coolant temperature sensor P0118
0118Engine coolant temperature
sensor circuit high inputAn excessively high voltage from the sensor is
sent to ECM.
Detected items Engine operating condition in fail-safe mode
Engine coolant temper-
ature sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning ignition switch “ON”
or “START”. CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned ON or Start 40°C (104°F)
More than approx. 4 minutes after ignition ON or
Sta r t80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is a ctiva ted , th e co oling fan operates wh ile
engine is running.