2003 NISSAN ALMERA N16 stop start

ENGINE CONTROL SYSTEM
EC-23
[QG (WITH EURO-OBD)]
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EC
System ChartEBS00K34
*1: This sensor is not used to control the engine system under normal conditions.
*2: The signals are sent to the ECM through CAN communication line.
*3: The output signals are sent from the ECM through CAN communication line.
Multiport Fuel Injection (MFI) SystemEBS00K35
INPUT/OUTPUT SIGNAL CHART
*1: Under normal conditions, this sensor is not for engine control operation.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
Input (Sensor) ECM Function Output (Actuator)
●Camshaft position sensor (PHASE)
●Crankshaft position sensor (POS)
●Mass air flow sensor
●Engine coolant temperature sensor
●Heated oxygen sensor 1
●Throttle position sensor
●Accelerator pedal position sensor
●Park/neutral position (PNP) switch
●Intake air temperature sensor
●Power steering pressure sensor
●Ignition switch
●Stop lamp switch
●Battery voltage
●Knock sensor
●Refrigerant pressure sensor
●Heated oxygen sensor 2*1
●TCM (Transmission control module)*2
●Air conditioner switch*2
●Vehicle speed signal*2
●Electrical load signal*2
Fuel injection & mixture ratio control Fuel injectors
Electronic ignition system Power transistor
Fuel pump control Fuel pump relay
On board diagnostic system
MI (On the instrument panel)
*3
Intake valve timing controlIntake valve timing control solenoid
valve
Heated oxygen sensor 1 heater control Heated oxygen sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control
Air conditioner relay
*3
Cooling fan control
Cooling fan relay*3
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
*3 and piston position
Fuel injection & mixture
ratio controlFuel injectors Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage
*3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2
*1Density of oxygen in exhaust gas
Vehicle speed signal
*2Vehicle speed
Air conditioner switch
*2Air conditioner operation

EC-24
[QG (WITH EURO-OBD)]
ENGINE CONTROL SYSTEM
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from the crankshaft position sensor (POS), the camshaft
position sensor (PHASE) and the mass air flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.

●During warm-up
●When starting the engine
●During acceleration
●Hot-engine operation
●When selector lever is changed from “N” to “D” (A/T models)
●High-load, high-speed operation

●During deceleration
●During high engine speed operation
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses
heated oxygen sensor 1 in the exhaust manifold to monitor if the engine operation is rich or lean. The ECM
adjusts the injection pulse width according to the sensor voltage signal. For more information about heated
oxygen sensor 1, refer to EC-155
. This maintains the mixture ratio within the range of stoichiometric (ideal air-
fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
●Deceleration and acceleration
●High-load, high-speed operation
●Malfunction of heated oxygen sensor 1 or its circuit
●Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature
●High engine coolant temperature
●During warm-up
●After shifting from “N” to “D” (A/T models)
●When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from heated oxygen
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
PBIB0121E

EC-32
[QG (WITH EURO-OBD)]
BASIC SERVICE PROCEDURE
PREPARATION
Before performing “Idle Air Volume Learning”, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
●Battery voltage: More than 12.9V (At idle)
●Engine coolant temperature: 70 - 95°C (158 - 203°F)
●PNP switch: ON
●Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting switch to the 1st position to light
only small lamps.
●Steering wheel: Neutral (Straight-ahead position)
●Vehicle speed: Stopped
●Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until “FLUID TEMP SE” in “DATA MONITOR” mode of “A/
T” system indicates less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-31, "Accelerator Pedal Released Position Learning" .
2. Perform EC-31, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PREPARATION” (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
6. Touch “START” and wait 20 seconds.
SEF217Z
SEF454Y

BASIC SERVICE PROCEDURE
EC-33
[QG (WITH EURO-OBD)]
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7. Make sure that “CMPLT” is displayed on CONSULT-II screen. If
“CMPLT” is not displayed, “Idle Air Volume Learning” will not be
carried out successfully. In this case, find the cause of the inci-
dent by referring to the “Diagnostic Procedure” below.
8. Rev up the engine two or three times and make sure that idle
speed and ignition timing are within the specifications.
Without CONSULT-II
NOTE:
●It is better to count the time accurately with a clock.
●It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
1. Perform EC-31, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-31, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PREPARATION” (previously mentioned) are in good order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MI stops
blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MI turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
13. If idle speed and ignition timing are not within the specification, ″Idle Air Volume Learning″ will not be car-
ried out successfully. In this case, find the cause of the incident by referring to the “Diagnostic Procedure”
below.
ITEM SPECIFICATION
Idle speed M/T: 700±50 rpm
A/T: 800±50 rpm (in “P” or “N” position)
Ignition timing M/T: 8±5° BTDC
A/T: 10±5° BTDC (in “P” or “N” position)
MBIB0238E
ITEM SPECIFICATION
Idle speed M/T: 700±50 rpm
A/T: 800±50 rpm (in “P” or “N” position)
Ignition timing M/T: 8±5° BTDC
A/T: 10±5° BTDC (in “P” or “N” position)
PBIB0665E

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-49
[QG (WITH EURO-OBD)]
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2. Perform “SELF-DIAGNOSTIC PROCEDURE (Without CONSULT-II)” in AT section titled “TROUBLE
DIAGNOSIS”, “Self-diagnosis”. (The engine warm-up step can be skipped when performing the diagnosis
only to erase the DTC.)
3. Select Mode 4 with GST (Generic Scan Tool).
How to Erase DTC ( No Tools)
1. If the ignition switch stays “ON” after repair work, be sure to turn ignition switch OFF” once.
2. Wait at least 10 seconds and then turn it “ON” (engine stopped) again.
3. Change the diagnostic test mode from Mode II to Mode I by depressing the accelerator pedal. Refer to
EC-51, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
●If the battery is disconnected, the emission-related diagnostic information will be lost after
approx. 24 hours.
●The following data are cleared when the ECM memory is erased.
–Diagnostic trouble codes
–1st trip diagnostic trouble codes
–Freeze frame data
–1st trip freeze frame data
–System readiness test (SRT) codes
–Test values
–Others
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
NATS (Nissan Anti-theft System)EBS00K3I
●If the security indicator lights up with the ignition switch in
the “ON” position or “NATS MALFUNCTION” is displayed
on “SELF-DIAG RESULTS” screen, perform self-diagnostic
results mode with CONSULT-II using NATS program card.
Refer to EL-386.
●Confirm no self-diagnostic results of NATS is displayed
before touching “ERASE” in “SELF-DIAG RESULTS” mode
with CONSULT-II.
●When replacing ECM, initialization of NATS system and reg-
istration of all NATS ignition key IDs must be carried out
with CONSULT-II using NATS program card.
Therefore, be sure to receive all keys from vehicle owner.
Regarding the procedures of NATS initialization and NATS ignition key ID registration, refer to
CONSULT-II operation manual, NATS.
Malfunction Indicator (MI)EBS00K3J
DESCRIPTION
The MI is located on the instrument panel.
1. The MI will light up when the ignition switch is turned ON without
the engine running. This is a bulb check.
●If the MI does not light up, refer to EL-129, or see EC-397 .
2. When the engine is started, the MI should go off.
If the MI remains on, the on board diagnostic system has
detected an engine system malfunction.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following four functions.
SEF515Y
SAT652J

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-68
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
OK or NG
OK >>INSPECTION END
NG >> GO TO 11.
11 . PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-31, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-31, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-31, "
Idle Air Volume Learning" .
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the construction of “Idle Air Volume Learning”.
2. GO TO 4.
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.M/T: 8 ± 5° BTDC
A/T: 10 ± 5° BTDC (in “P” or “N” position)
Is ″Idle Air Volume Learning″ carried out successfully?
M/T: 700 ± 50 rpm
A/T: 800 ± 50 rpm (in “P” or “N” position)
M/T: 700 ± 50 rpm
A/T: 800 ± 50 rpm (in “P” or “N” position)

EC-90
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
WORK SUPPORT MODE
Work Item
*: This function is not necessary in the usual service procedure.
SELF-DIAG RESULTS MODE
Self Diagnostic Item
Regarding items of “DTC and 1st trip DTC”, refer to EC-10, "INDEX FOR DTC" .
Freeze Frame Data and 1st Trip Freeze Frame Data
*1: The items are the same as those of 1st trip freeze frame data. WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASE
●FUEL PUMP WILL STOP BY TOUCHING “START” DUR-
ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.When releasing fuel pressure
from fuel line
IDLE AIR VOL LEARN
●THE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM.When learning the idle air volume
SELF-LEARNING CONT
●THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT.When clearing the coefficient of
self-learning control value
TARGET IDLE RPM ADJ
*●IDLE CONDITION When setting target idle speed
TARGET IGN TIM ADJ
*●IDLE CONDITION When adjusting target ignition tim-
ing
After adjustment, confirm target
ignition timing with a timing light.
Freeze frame data
item*1Description
DIAG TROUBLE
CODE
[PXXXX]
●The engine control component part/control system has a trouble code, it is displayed as “PXXXX”. (Refer
to EC-10, "
INDEX FOR DTC" .)
FUEL SYS-B1
●“Fuel injection system status” at the moment a malfunction is detected is displayed.
●One mode in the following is displayed.
“MODE 2”: Open loop due to detected system malfunction
“MODE 3”: Open loop due to driving conditions (power enrichment, deceleration enrichment)
“MODE 4”: Closed loop - using oxygen sensor(s) as feedback for fuel control
“MODE 5”: Open loop - has not yet satisfied condition to go to closed loop
CAL/LD VALUE [%]
●The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP [°C]
or [°F]
●The engine coolant temperature at the moment a malfunction is detected is displayed.
L-FUEL TRIM-B1 [%]
●“Long-term fuel trim” at the moment a malfunction is detected is displayed.
●The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule
than short-term fuel trim.
S-FUEL TRIM-B1 [%]
●“Short-term fuel trim” at the moment a malfunction is detected is displayed.
●The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel
schedule.
ENGINE SPEED
[rpm]
●The engine speed at the moment a malfunction is detected is displayed.
VHCL SPEED [km/h]
or [mph]
●The vehicle speed at the moment a malfunction is detected is displayed.
B/FUEL SCHDL
[msec]
●The base fuel schedule at the moment a malfunction is detected is displayed.
INT/A TEMP SE [°C]
or [°F]
●The intake air temperature at the moment a malfunction is detected is displayed.