2014 NISSAN TEANA engine

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.
JPBIA5972GB
JPBIA6226GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

EC-54
< SYSTEM DESCRIPTION >[QR25DE]
SYSTEM
Also, except when idling and during low engine coolant te
mperature, this system opens the intake manifold
runner control valve.
In this condition, this system tends to increase power by improving intake efficiency via reduction of intake flow
resistance.
The intake manifold runner control valve is operated by the ECM.
INTAKE MANIFOLD TUNING SYSTEM
INTAKE MANIFOLD TUNING SYSTEM : System DescriptionINFOID:0000000009462099
SYSTEM DIAGRAM
SYSTEM DESCRIPTION
This system switches the length of intake air path according to the low-to-medium speed range or high speed
range. Torque is increased in the low-to-medium sp eed range and the engine output is improved in the high
speed range.
Engine speed: Low and medium speed range
Since the intake manifold tuning (IMT) valve is closed when the engine speed is less than 5,000 rpm, the
length of the effective intake air path is from the mouth of intake manifold collector to the intake valve. This
long path brings the inertia effect of intake air, cont ributing to the improvement in intake air efficiency and the
generation of high torque.
Engine speed: High speed range
When engine speed is 5,000 rpm or more, ECM turns ON the intake manifold tuning valve motor to open the
intake manifold tuning valve. The length of the effective in take air path at this time is from the intake manifold
tuning valve to the intake valve. This short path brings the inertia effect of intake air in the high speed range,
contributing to the torque improvement while the engine is running at high speeds. (The highest engine output
is improved.)
JPBIA5974GB
JPBIA5935GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

SYSTEMEC-55
< SYSTEM DESCRIPTION > [QR25DE]
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Intake Manifold Tuning Valve Operating Condition
ECM opens the intake manifold tuning valve when all of the following conditions are satisfied.
• Engine speed: 5,000 rpm or more
• Engine coolant temperature: -30 °C (-22 °F) or more
• Battery voltage: 16 V or less
ENGINE PROTECTION CONTROL AT LOW ENGINE OIL PRESSURE
ENGINE PROTECTION CONTROL AT LOW ENGINE OIL PRESSURE : System De-
scription
INFOID:0000000009462100
SYSTEM DIAGRAM
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
• The engine protection control at low engine oil pressure warns the driver of a decrease in engine oil pres-
sure by the oil pressure warning lamp a before the engine becomes damaged.
• When detecting a decrease in engine oil pressure at an engine speed less than 1,000 rpm, ECM transmits an oil pressure warning lamp signal to the combination meter.The combination meter turns ON the oil pres-
sure warning lamp, according to the signal.
*: When detecting a normal engine oil pressure, ECM turns OFF the oil pressure warning lamp.
FUEL FILLER CAP WARNING SYSTEM
JPBIA4922GB
Sensor Input signal to ECM ECM function Actuator
Engine oil pressure sensor Engine pressure Engine protection control
• Oil pressure warning lamp
signal
•FUel cut control Combination meter
• Oil pressure warning lamp
Crankshaft position sensor
(POS) Engine speed
Engine oil temperature sensor Engine oil temperature
Decrease in engine oil pressure Engine speed Combination meter
Fuel cut
Oil pressure warning lamp
Detection Less than 1,000 rpm ON* NO
1,000 rpm or more ON YES
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

SYSTEMEC-57
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tioner)INFOID:0000000009462102
SYSTEM DIAGRAM
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
• When cranking the engine.
• At high engine speeds.
• When the engine coolant temperature becomes excessively high.
• When operating power steering during low engine speed or low vehicle speed.
• When engine speed is excessively low.
• When refrigerant pressure is excessively low or high.
AIR CONDITIONING CUT CONTROL : System Description (with manual air condition-
JPBIA5979GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

EC-58
< SYSTEM DESCRIPTION >[QR25DE]
SYSTEM
er)
INFOID:0000000009462103
SYSTEM DIAGRAM
SYSTEM DESCRIPTION
This system improves engine operati on when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
• When cranking the engine.
• At high engine speeds.
• When the engine coolant temperat ure becomes excessively high.
• When operating power steering during low engine speed or low vehicle speed.
• When engine speed is excessively low.
• When refrigerant pressure is excessively low or high.
COOLING FAN CONTROL
JPBIA6222GB
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SYSTEMEC-59
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COOLING FAN CONTROL : System Descripti
on (with automatic air conditioner)
INFOID:0000000009462104
SYSTEM DIAGRAM
SYSTEM DESCRIPTION
ECM controls cooling fan speed corresponding to vehicle speed, engine coolant temperature, refrigerant pres-
sure, air conditioner ON signal. Then control syst em has 4-step control [HIGH/MIDDLE/LOW/OFF].
Cooling Fan Operation
Cooling Fan Relay Operation
The ECM controls cooling fan relays through CAN communication line.
JPBIA3233GB
JMBIA0179GB
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EC-60
< SYSTEM DESCRIPTION >[QR25DE]
SYSTEM
COOLING FAN CONTROL : S ystem Description (with manual air conditioner)
INFOID:0000000009462105
SYSTEM DIAGRAM
SYSTEM DESCRIPTION
ECM controls cooling fan speed corresponding to vehicle speed, engine coolant temperature, refrigerant pres-
sure, air conditioner ON signal. Then control syst em has 4-step control [HIGH/MIDDLE/LOW/OFF].
Cooling fan speed Cooling fan relay
123
Stop (OFF) OFF OFF OFF
Low (LOW) ON OFF OFF
Middle (MID) OFF ON OFF
High (HI) OFF ON ON
JPBIA6223GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

EC-62
< SYSTEM DESCRIPTION >[QR25DE]
SYSTEM
EVAPORATIVE EMISSION SYSTEM : System Description
INFOID:0000000009462106
SYSTEM DIAGRAM
INPUT/OUTPUT SIGNAL CHART
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
JPBIA4896GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
EVAP canister
purge flow control EVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio fe edback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
EVAP control system pressure sensor Pressure in purge line
Combination meter Vehicle speed*
2
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM