2003 NISSAN TEANA engine control

EC-8 Diagnostic Procedure ...........................................648
Component Inspection ..........................................651
Removal and Installation ......................................651
DTC P2138 APP SENSOR .....................................652
Component Description ........................................652
CONSULT-II Reference Value in Data Monitor Mode
.652
On Board Diagnosis Logic ....................................652
DTC Confirmation Procedure ...............................653
Wiring Diagram .....................................................654
Diagnostic Procedure ...........................................655
Component Inspection ..........................................659
Removal and Installation ......................................659
ASCD BRAKE SWITCH ..........................................660
Component Description ........................................660
CONSULT-II Reference Value in Data Monitor Mode
.660
Wiring Diagram .....................................................661
Diagnostic Procedure ...........................................662
Component Inspection ..........................................666
ASCD INDICATOR ..................................................667
Component Description ........................................667
CONSULT-II Reference Value in Data Monitor Mode
.667
Wiring Diagram .....................................................668
Diagnostic Procedure ...........................................669
ELECTRICAL LOAD SIGNAL ................................670
Description ............................................................670
CONSULT-II Reference Value in Data Monitor Mode
.670
Diagnostic Procedure ...........................................670
ELECTRONIC CONTROLLED ENGINE MOUNT ..672
System Description ...............................................672
CONSULT-II Reference Value in Data Monitor Mode
.672
Wiring Diagram .....................................................673
Diagnostic Procedure ...........................................674
EVAP CANISTER PURGE VOLUME CONTROL
SOLENOID VALVE .................................................677
Description ............................................................677
CONSULT-II Reference Value in Data Monitor Mode
.677
Wiring Diagram .....................................................678
Diagnostic Procedure ...........................................680
Component Inspection ..........................................683
Removal and Installation ......................................683
FUEL INJECTOR ....................................................684
Component Description ........................................684
CONSULT-II Reference Value in Data Monitor Mode
.684
Wiring Diagram .....................................................685
Diagnostic Procedure ...........................................686
Component Inspection ..........................................689
Removal and Installation ......................................689
FUEL PUMP ............................................................690
Description ............................................................690
CONSULT-II Reference Value in Data Monitor Mode
.690
Wiring Diagram .....................................................691Diagnostic Procedure ............................................692
Component Inspection ..........................................695
Removal and Installation .......................................695
HO2S1 .....................................................................696
Component Description ........................................696
CONSULT-II Reference Value in Data Monitor Mode
.696
Wiring Diagram .....................................................697
Diagnostic Procedure ............................................700
Component Inspection ..........................................704
Removal and Installation .......................................705
HO2S1 HEATER ......................................................706
Description ............................................................706
CONSULT-II Reference Value in Data Monitor Mode
.706
Wiring Diagram .....................................................707
Diagnostic Procedure ............................................711
Component Inspection ..........................................713
Removal and Installation .......................................713
HO2S2 .....................................................................714
Component Description ........................................714
CONSULT-II Reference Value in Data Monitor Mode
.714
Wiring Diagram .....................................................715
Diagnostic Procedure ............................................718
Component Inspection ..........................................720
Removal and Installation .......................................722
HO2S2 HEATER ......................................................723
Description ............................................................723
CONSULT-II Reference Value in Data Monitor Mode
.723
Wiring Diagram .....................................................724
Diagnostic Procedure ............................................727
Component Inspection ..........................................729
Removal and Installation .......................................729
IAT SENSOR ...........................................................730
Component Description ........................................730
Wiring Diagram .....................................................731
Diagnostic Procedure ............................................732
Component Inspection ..........................................734
Removal and Installation .......................................734
IGNITION SIGNAL ..................................................735
Component Description ........................................735
Wiring Diagram .....................................................736
Diagnostic Procedure ............................................741
Component Inspection ..........................................746
Removal and Installation .......................................747
REFRIGERANT PRESSURE SENSOR ..................748
Component Description ........................................748
Wiring Diagram .....................................................749
Diagnostic Procedure ............................................750
Removal and Installation .......................................752
VIAS .........................................................................753
Description ............................................................753
CONSULT-II Reference Value in Data Monitor Mode
.754
Wiring Diagram .....................................................755
Diagnostic Procedure ............................................757

EC-9
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ECA
Component Inspection ......................................... 760
Removal and Installation ...................................... 761
VSS ......................................................................... 762
Description ........................................................... 762
Diagnostic Procedure ........................................... 762
MI & DATA LINK CONNECTORS .......................... 763
Wiring Diagram .................................................... 763
SERVICE DATA AND SPECIFICATIONS (SDS) .... 765
Fuel Pressure ....................................................... 765
Idle Speed and Ignition Timing ............................. 765Mass Air Flow Sensor ...........................................765
Intake Air Temperature Sensor .............................765
Engine Coolant Temperature Sensor ...................765
Heated Oxygen Sensor 1 Heater .........................765
Heated Oxygen sensor 2 Heater ..........................765
Crankshaft Position Sensor (POS) .......................765
Camshaft Position Sensor (PHASE) ....................765
Throttle Control Motor ...........................................765
Fuel Injector ..........................................................765
Fuel Pump ............................................................766

PRECAUTIONS
EC-15
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Do not disassemble ECM.

If a battery cable is disconnected, the memory will return to
the ECM value.
The ECM will now start to self-control at its initial value.
Engine operation can vary slightly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.

If the battery is disconnected, the following emission-
related diagnostic information will be lost within 24 hours.
–Diagnostic trouble codes
–1st trip diagnostic trouble codes
–Freeze frame data
–1st trip freeze frame data

When connecting ECM harness connector, fasten it
securely with levers as far as they will go as shown in the
figure.

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-415, "
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
PBIB2466E
PBIB0090E
MEF040D

PRECAUTIONS
EC-17
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EC


Do not depress accelerator pedal when starting.

Immediately after starting, do not rev up engine unneces-
sarily.

Do not rev up engine just prior to shutdown.

When installing C.B. ham radio or a mobile phone, be sure
to observe the following as it may adversely affect elec-
tronic control systems depending on installation location.
–Keep the antenna as far as possible from the electronic
control units.
–Keep the antenna feeder line more than 20 cm (8 in) away
from the harness of electronic controls.
Do not let them run parallel for a long distance.
–Adjust the antenna and feeder line so that the standing-
wave radio can be kept smaller.
–Be sure to ground the radio to vehicle body.
SEF709Y
SEF708Y

EC-20
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ENGINE CONTROL SYSTEM

ENGINE CONTROL SYSTEMPFP:23710
System DiagramBBS005BE
PBIB3287E

ENGINE CONTROL SYSTEM
EC-21
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Multiport Fuel Injection (MFI) SystemBBS005BF
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*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
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 both the crankshaft position sensor 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

High-load, high-speed operation


During deceleration

During high engine speed operation
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
3
Piston position
Fuel injection & mixture
ratio controlFuel injector 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
Wheel sensor
Vehicle speed*
2
Air conditioner switch
Air conditioner operation*2

EC-22
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ENGINE CONTROL SYSTEM

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 whether 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-143
. 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

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-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., fuel 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.
PBIB2953E

ENGINE CONTROL SYSTEM
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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 fuel 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) SystemBBS005BG
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.
SYSTEM DESCRIPTION
Firing order: 1-3-4-2
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Comput-
ing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revised by the ECM according to the other data stored in
the ECM.

At starting

During warm-up

At idle

At low battery voltage

During acceleration
SEF337W
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2
Piston position
Ignition timing
controlPower transistor Camshaft position sensor (PHASE)
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
Wheel sensor
Vehicle speed*1