2014 NISSAN TEANA fuel

SYSTEMEC-43
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MULTIPORT FUEL INJECTION SYSTEM
MULTIPORT FUEL INJECTION SYSTEM : S
ystem Description (with automatic air
P052A
P052B Intake valve timing intermedi-
ate lock control ——
× —
P0603 ECM power supply circuit — ×——
P0605 ECM — ×——
P0643 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.
P1078 Exhaust valve timing control position sensor circuit ×
— × —
P1805 Brake switch
———ECM controls the electric throttle control actuator by regulat-
ing the throttle opening to a small range.
Therefore, acceleration will be poor.
Vehicle condition Driving condition
When engine is idling Normal When accelerating Poor acceleration
P2004 Intake manifold runner control valve —
×× —
P2100
P2103 Throttle contro
l 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.
P2101 Electric throttle control func- tion ——— ECM stops the electric throttle control actuator control, throttle
valve is maintained at a fixed opening (approx. 5 degrees) by
the return spring.
P2118 Throttle control motor ———ECM stops the electric throttle control actuator control, throttle
valve is maintained at a fixed opening (approx. 5 degrees) by
the return spring.
P2119 Electric thro ttle control actua-
tor —
×——
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor
———The ECM controls the electric throttle control actuator in reg-
ulating 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 normal condition.
So, the acceleration will be poor.
DTC
No. Detected items Vehicle behavior
Pattern Others
ABC
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EC-44
< SYSTEM DESCRIPTION >[QR25DE]
SYSTEM
conditioner)
INFOID:0000000009462093
SYSTEM DIAGRAM
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). T he amount of fuel injected is a program value in the
ECM memory. The program value is preset by engi ne operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from t he crankshaft position sensor (POS), camshaft position
sensor (PHASE) and the ma ss air flow sensor.
VARIOUS FUEL INJECTION I NCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated 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
JPBIA5978GB
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SYSTEMEC-45
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MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov
ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better r educe CO, HC and NOx emissions. This system uses A/F
sensor 1 in the exhaust manifold to monitor whether t he engine operation is rich or lean. The ECM adjusts the
injection pulse width according to the sensor voltage si gnal. For more information about A/F sensor 1, refer to
EC-32, "Air Fuel Ratio (A/F) Sensor 1"
. This maintains the mixture rati o 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 th ree way catalyst (manifold). Even if the switching
characteristics of A/F sensor 1 shift, the air-fuel rati o is controlled to stoichiometric by the signal from heated
oxygen sensor 2.
• Open Loop Control
The open loop system condition refers to when the EC M 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 A/F sensor 1 or its circuit
- Insufficient activation of A/F 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 A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM cont rols the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mi xture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing 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 co mpared 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 compensati on used to maintain the mixture ratio at its theoretical
value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical 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 ca rried 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.
PBIB2793E
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EC-46
< SYSTEM DESCRIPTION >[QR25DE]
SYSTEM
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 cylinder s 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, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speeds.
MULTIPORT FUEL INJECTION SYSTEM : S ystem Description (with manual air con-
ditioner)
INFOID:0000000009462094
SYSTEM DIAGRAM
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). T he amount of fuel injected is a program value in the
ECM memory. The program value is preset by engi ne operating conditions. These conditions are determined
SEF337W
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SYSTEMEC-47
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by input signals (for engine speed and intake air) from t
he crankshaft position sensor (POS), camshaft position
sensor (PHASE) and the mass air flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated 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
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better r educe CO, HC and NOx emissions. This system uses A/F
sensor 1 in the exhaust manifold to monitor whether t he engine operation is rich or lean. The ECM adjusts the
injection pulse width according to the sensor voltage si gnal. For more information about A/F sensor 1, refer to
EC-32, "Air Fuel Ratio (A/F) Sensor 1"
. This maintains the mixture rati o 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 th ree way catalyst (manifold). Even if the switching
characteristics of A/F sensor 1 shift, the air-fuel rati o is controlled to stoichiometric by the signal from heated
oxygen sensor 2.
• Open Loop Control
The open loop system condition refers to when the EC M 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 A/F sensor 1 or its circuit
- Insufficient activation of A/F 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 A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM cont rols the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mi xture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing 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 co mpared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
PBIB2793E
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

EC-48
< SYSTEM DESCRIPTION >[QR25DE]
SYSTEM
“Short term fuel trim” is the short-term fuel compensati
on used to maintain the mixture ratio at its theoretical
value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical 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 carri ed out long-term to compensate for continual deviation
of the short term fuel trim from t he 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 cylinder s 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, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speeds.
ELECTRIC IGNITION SYSTEM
ELECTRIC IGNITION SYSTEM : System DescriptionINFOID:0000000009462095
SYSTEM DIAGRAM
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.
SEF337W
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SYSTEMEC-49
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The ECM receives information such as the injecti
on pulse width and camshaft position sensor (PHASE) sig-
nal. Computing this information, ignition si gnals are transmitted to the power transistor.
During the following conditions, the ignition timing is revi sed 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
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL : System DescriptionINFOID:0000000009462096
INTAKE VALVE TIMING CONTROL
System Diagram
Input/Output Signal Chart
*: This signal is sent to the ECM through CAN communication line
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Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed and piston position
Intake valve
timing control Intake valve timing control
solenoid valve
Camshaft position sensor (PHASE)
Engine oil temperature sensor Engine oil temperature
Engine coolant temperature sensor Engine coolant temperature
Combination meter Vehicle speed*
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SYSTEMEC-53
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SYSTEM DESCRIPTION
This mechanism hydraulically controls cam phases c
ontinuously with the fixed operating angle of the exhaust
valve.
The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine oil tem-
perature. Then, the ECM sends ON/OFF pulse duty signal s to the exhaust valve timing (EVT) control solenoid
valve depending on driving status. This makes it possible to control the shut/open timing of the exhaust valve
to increase engine torque and output in a range of high engine speed.
INTAKE MANIFOLD RUNNER CONTROL
INTAKE MANIFOLD RUNNER CONTROL : System DescriptionINFOID:0000000009462098
SYSTEM DIAGRAM
SYSTEM DESCRIPTION
Intake manifold runner control valve has a valve portion in the intake passage of each cylinder.
While idling and during low engine coolant temperature, t he intake manifold runner control valve closes. Thus
the velocity of the air in the intake passage increases , promoting the vaporization of the fuel and producing a
intake manifold runner in the combustion chamber.
Because of this operation, this system tends to in crease the burning speed of the gas mixture, improve
exhaust emission, and increase the stability in running conditions.
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