2003 NISSAN ALMERA N16 Engine control circuit

EC-64
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
●When there is an open circuit on MI circuit, the ECM cannot warn the driver by lighting MI up when there
is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MI circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MI circuit and demands the driver to
repair the trouble.
P0117
P0118Engine coolant tempera-
ture 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 Start40°C (104°F)
More than approx. 4 minutes after
ignition ON or Start80°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 activated, the cool-
ing fan operates while engine is running.
P0221
P0222
P0223
P1223
P1224Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening
in order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the nor-
mal condition.
So, the acceleration will be poor.
P0226
P0227
P0228
P1227
P1228Accelerator pedal position
sensorThe ECM controls the electric throttle control actuator in regulating the throttle opening
in order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the nor-
mal condition.
So, the acceleration will be poor.
P1121 Electric throttle control actu-
ator
(ECM detect the throttle
valve is stuck open.)While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops,
the engine stalls.
The engine can restart in “N” or “P” position, and engine speed will not exceed 1,000
rpm or more.
P1122 Electric throttle control func-
tionECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1124
P1126Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1128
Throttle control motorECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring
P1229 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring. DTC No. Detected items Engine operating condition in fail-safe mode
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-70
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
Symptom Matrix Chart
EBS00K3P
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 11232 22 3 2EC-381
Fuel pressure regulator system334444444 4EC-34
Injector circuit 11232 22 2EC-375
Evaporative emission system 334444444 4EC-251,
EC-399
Air Positive crankcase ventilation sys-
tem334444444 41EC-402
Incorrect idle speed adjustment 33 1111 1EC-65
Electric throttle control actuator 112332222 2 2EC-276
,
EC-278
,
EC-285
,
EC-291
IgnitionIncorrect ignition timing adjustment33111 11 1EC-65
Ignition circuit 11222 22 2EC-365
Main power supply and ground circuit 22333 33 23EC-110
Mass air flow sensor circuit 11222 22 2EC-134
Engine coolant temperature sensor circuit 11222322312EC-144
Throttle position sensor circuit 12 22222 2EC-199
,
EC-205
,
EC-335
,
EC-341
,
EC-343
,
EC-352
Accelerator pedal position sensor circuit3212 2EC-211
,
EC-218
,
EC-345
Heated oxygen sensor 1 circuit 1232 22 2EC-149
,
EC-155
,
EC-165
,
EC-296
,
EC-302
Knock sensor circuit 2 2 3EC-230
Crankshaft position sensor (POS) circuit 2 2EC-234
Camshaft position sensor (PHASE) circuit 2 2EC-240
Vehicle speed signal circuit 2 3 3 3EC-257

TROUBLE DIAGNOSIS
EC-71
[QG (WITH EURO-OBD)]
C
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EC
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Power steering pressure sensor circuit 2 3 3 3 3EC-260
ECM 22333333333EC-265,
EC-268
Intake valve timing control solenoid valve cir-
cuit332 13223 3EC-272
PNP switch circuit 3 33333 3EC-356
Refrigerant pressure sensor circuit 2 3 3 3 3 4EC-387
Electrical load signal circuit 3 3 3 3EC-392
Air conditioner circuit223333333 3 2AT C - 2 9
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank
5
5FE-4
Fuel piping 5 5 5 5 5 5 FE-4
Vapor lock—
Valve deposit
555555 5—
Poor fuel (Heavy weight gaso-
line, Low octane)—

EC-72
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
Air Air duct
55555 5EM-14
Air cleanerEM-14
Air leakage from air duct
(Mass air flow sensor —electric
throttle control actuator)
5555EM-14
Electric throttle control actuatorEM-16
Air leakage from intake manifold/
Collector/GasketEM-16
Cranking Battery
111111 11SC-3
Alternator circuitSC-27
Starter circuit 3 SC-13
Signal plate/Flywheel/Drive plate 6EM-70
PNP switch
4AT- 11 6,
MT-21
Engine Cylinder head
55555 55 5EM-57
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-70
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nismTimin g c hain
55555 55 5EM-47
CamshaftEM-32
Intake valve timing controlEM-47
Intake valve
3EM-57
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-19
, FE-
26
Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery
55555 55 52EM-22
, LC-
5, LC-9,
LC-4
Oil level (Low)/Filthy oilLC-8 SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA

EC-122
[QG (WITH EURO-OBD)]
DTC P0031, P0032 HO2S1 HEATER
DTC P0031, P0032 HO2S1 HEATER
PFP:22690
DescriptionEBS00K4H
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the heated oxygen sensor 1 heater corresponding to the engine
speed and engine coolant temperature. The duty percent varies with engine coolant temperature when engine
is started.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeEBS00K4I
Specification data are reference values.
On Board Diagnosis LogicEBS00K4J
DTC Confirmation ProcedureEBS00K4K
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:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
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.
Sensor Input Signal to ECM ECM Function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 1
heater controlHeated oxygen sensor 1
heater
Engine coolant temperature sensor Engine coolant temperature
Engine speed rpm Heated oxygen sensor 1 heater
Above 3,200 (A/T models)
Above 3,600 (M/T models)OFF
Below 3,200 after warning up (A/T models).
Below 3,600 after warning up (M/T models).ON
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 HTR (B1)
●Engine: After warming up
●Engine speed: Below 3,200 rpm (A/T models)
Below 3,600 rpm (M/T models)ON
●Engine speed: Above 3,200 rpm (A/T models)
Above 3,600 rpm (M/T models)OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0031
0031Heated oxygen sensor 1
heater control circuit lowThe current amperage in the heated oxygen sensor
1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 1 heater.)
●Harness or connectors
(The heated oxygen sensor 1 heater
circuit is open or shorted.)
●Heater oxygen sensor 1 heater
P0032
0032Heated oxygen sensor 1
heater control circuit highThe current amperage in the heated oxygen sensor
1 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 1 heater.)
●Harness or connectors
(The heated oxygen sensor 1 heater
circuit is shorted.)
●Heater oxygen sensor 1 heater

EC-128
[QG (WITH EURO-OBD)]
DTC P0037, P0038 HO2S2 HEATER
DTC P0037, P0038 HO2S2 HEATER
PFP:226A0
DescriptionEBS00K4P
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 ModeEBS00K4Q
Specification data are reference values.
On Board Diagnosis LogicEBS00K4R
DTC Confirmation ProcedureEBS00K4S
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:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch “ON” and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch ″OFF″ and wait at least 10 seconds.
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 sensorEngine coolant tempera-
ture
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
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0037
0037Heated oxygen sensor 2
heater control circuit lowThe current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)
●Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
●Heater oxygen sensor 2 heater
P0038
0038Heated oxygen sensor 2
heater control circuit highThe current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)
●Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
●Heater oxygen sensor 2 heater

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 P0133 HO2S1
EC-161
[QG (WITH EURO-OBD)]
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5.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 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 P0171 or P0172 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171 or DTC P0172 (Refer to EC-186 or EC-193 ).
No >> GO TO 6.
6.CHECK HO2S1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect heated oxygen sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 74 and HO2S1
terminal 3. Refer to Wiring Diagram.
5. 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.
SEF215Z
MBIB0096E
Continuity should exist.
MBIB0091E