2003 NISSAN ALMERA N16 ecm

EC-14
[QG (WITH EURO-OBD)]
INDEX FOR DTC
*1: 1st trip DTC No. is the same as DTC No.
*2: These numbers are prescribed by ISO 15031-5.
*3: In Diagnostic Test Mode II (Self-diagnostic results), these numbers are controlled by NISSAN.
*4: When engine is running.
*5: The trouble shooting for this DTC needs CONSULT-II.
*6: When the fail-safe operations for both self-diagnoses occur, the MI illuminates. P1217 1217 ENG OVER TEMP 1×EC-324
P1223 1223 TP SEN 2/CIRC 1×EC-335
P1224 1224 TP SEN 2/CIRC 1×EC-335
P1225 1225 CTP LEARNING 2 –EC-341
P1226 1226 CTP LEARNING 2 –EC-343
P1227 1227 APP SEN 2/CIRC 1×EC-345
P1228 1228 APP SEN 2/CIRC 1×EC-345
P1229 1229 SENSOR POWER/CIRC 1×EC-352
P1610 - P1615 1610 - 1615 NATS MALFUNCTION 2 –EC-49
P1705 1705 TPV SEN/CIRC A/T 1×AT-181
P1706 1706 P-N POS SW/CIRCUIT 2×EC-356
P1760 1760 O/R CLTCH SOL/CIRC 2×AT-187
P1805 1805 BRAKE SW/CIRCUIT 2 –EC-360
DTC*1
Items
(CONSULT-II screen terms)TripMI lighting
upReference page
CONSULT-II
GST*
2ECM*3

PRECAUTIONS
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PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EBS00K2V
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. Information necessary to service the system safely is included in the SRS and SB section of
this Service Manual.
WARNING:
●To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.
●Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.
●Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harness connec-
tors.
On Board Diagnostic (OBD) System of Engine and A/TEBS00K2W
The ECM has an on board diagnostic system. It will light up the malfunction indicator (MI) to warn the driver of
a malfunction causing emission deterioration.
CAUTION:
●Be sure to turn the ignition switch OFF and disconnect the battery ground cable before any repair
or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc. will
cause the MI to light up.
●Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MI to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
●Certain systems and components, especially those related to OBD, may use a new style slide-
locking type harness connector. For description and how to disconnect, refer to EL-7.
●Be sure to route and secure the harnesses properly after work. The interference of the harness
with a bracket, etc. may cause the MI to light up due to the short circuit.
●Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MI to light up due to the malfunction of the fuel injection system, etc.
●Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionEBS00K2X
●Always use a 12 volt battery as power source.
●Do not attempt to disconnect battery cables while engine is
running.
●Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect battery
ground cable. Failure to do so may damage the ECM
because battery voltage is applied to ECM even if ignition
switch is turned off.
●Before removing parts, turn ignition switch OFF and then
disconnect battery ground cable.
SEF289H

EC-16
[QG (WITH EURO-OBD)]
PRECAUTIONS
●Do not disassemble ECM.
●If battery cable is disconnected, the memory will return to
the initial ECM values.
The ECM will now start to self-control at its initial values.
Engine operation can vary slightly when the cable is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.
●When connecting ECM harness connector, fasten it
securely with levers as far as they will go as shown at right.
●When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.
●Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.
●Keep engine control system harness at least 10 cm (4 in)
away from adjacent harness, to prevent engine control sys-
tem malfunctions due to receiving external noise, degraded
operation of ICs, etc.
●Keep engine control system parts and harness dry.
●Before replacing ECM, perform “ECM Terminals and Refer-
ence Value” inspection and make sure ECM functions prop-
erly. Refer to EC-80, "
ECM Terminals and Reference Value" .
●Handle mass air flow sensor carefully to avoid damage.
●Do not disassemble mass air flow sensor.
●Do not clean mass air flow sensor with any type of deter-
gent.
●Do not disassemble electric throttle control actuator.
●Even a slight leak in the air intake system can cause seri-
ous incidents.
●Do not shock or jar the camshaft position sensor (PHASE),
crankshaft position sensor (POS).
PBIB1164E
MBIB0145E
PBIB0090E
MEF040D

PRECAUTIONS
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●After performing each TROUBLE DIAGNOSIS, perform
“DTC Confirmation Procedure” or “Overall Function
Check”.
The DTC should not be displayed in the “DTC Confirmation
Procedure” if the repair is completed. The “Overall Func-
tion Check” should be a good result if the repair is com-
pleted.
●When measuring ECM signals with a circuit tester, connect
a break-out box (SST) and Y-cable adapter (SST) between
the ECM and ECM harness connector.
●When measuring ECM signals with a circuit tester, never
allow the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.
●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.
●Do not operate fuel pump when there is no fuel in lines.
●Tighten fuel hose clamps to the specified torque.
SAT652J
SEF348N
MBIB0046E

PREPARATION
EC-19
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PREPARATIONPFP:00002
Special Service ToolsEBS00K2Z
Commercial Service ToolsEBS00K30
Tool number
Tool nameDescription
KV10117100
Heated oxygen
sensor wrenchLoosening or tightening heated oxygen sensors
with 22 mm (0.87 in) hexagon nut
KV10114400
Heated oxygen
sensor wrenchLoosening or tightening heated oxygen sensors
a: 22 mm (0.87 in)
KV109E0010
Break-out boxMeasuring the ECM signals with a circuit tester
KV109E0080
Y-cable adapterMeasuring the ECM signals with a circuit tester
S-NT379
S-NT636
S-NT825
S-NT826
Tool name Description
Quick connector
releaseRemoving fuel tube quick connectors in engine
room
(Available in SEC. 164 of PARTS CATALOG: Part
No. 16441 6N210)
Fuel filler cap adapter Checking fuel tank vacuum relief valve opening
pressure
PBIC0198E
S-NT653

ENGINE CONTROL SYSTEM
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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

ENGINE CONTROL SYSTEM
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inally designed. Both manufacturing differences (i.e., mass air flow sensor hot film) and characteristic changes
during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN compared
to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an
increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Electronic Ignition (EI) SystemEBS00K36
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SEF337W
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
*2 and piston position
Ignition timing control Power transistor Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage
*2
Vehicle speed signal*1Vehicle speed