2014 NISSAN TEANA coolant temperature

COMPONENT PARTSEC-559
< SYSTEM DESCRIPTION > [VQ35DE]
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FUEL LEVEL SENSOR
The fuel level sensor is mounted in the fuel level sensor unit.
The sensor detects a fuel level in the fuel tank and tr ansmits a signal to the combination meter. The combina-
tion meter sends the fuel level sensor signal to the ECM via the CAN communication line.
It consists of two parts, one is mechanical float and the ot her is variable resistor. Fuel level sensor output volt-
age changes depending on the movement of the fuel mechanical float.
FUEL TANK TEMPERATURE SENSOR
The fuel tank temperature sensor is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a ther mistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

*: These data are reference values and are measured between ECM terminals 95 (Fuel tank temperature sensor) and ground.
Heated Oxygen Sensor 2INFOID:0000000009462500
DESCRIPTION
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air fuel ratio is c ontrolled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1 V in richer conditions to 0 V in leaner con-
ditions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
HEATED OXYGEN SENSOR 2 HEATER
Heated oxygen sensor 2 heater is integrated in the sensor.
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown above Sto ps .
Fluid temperature
[° C ( °F)] Voltage*
(V) Resistance
(kΩ)
20 (68) 3.5 2.3 - 2.7
50 (122) 2.2 0.79 - 0.90
SEF012P
SEF327R
Engine speed Heated oxygen sensor 2 heater
Above 3,600 rpm OFF
Below 3,600 rpm after the following conditions are met.
• Engine: After warming up
• Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no load ON
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

SYSTEMEC-567
< SYSTEM DESCRIPTION > [VQ35DE]
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P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT display)
Just as ignition switch is turned ON
or START 40
°C (104 °F)
Approx 4 minutes or more after en-
gine starting 80
°C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135 Throttle 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 normal
condition.
Therefore, the acceleration will be poor.
P0196
P0197
P0198 Engine oil temperature
sensor Intake valve timing control does not function.
P0500 Vehicle speed sensor The cooling fan operates (Highest) while engine is running.
P0524 Engine oil pressure • ECM illuminates oil pressure warning lamp on the combination meter.
• Engine speed will not rise more than 4,000 rpm due to the fuel cut.
• Fail-safe is canceled when ignition switch OFF → ON.
P0605 ECM (When ECM calculation function is malfunctioning:) ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
ECM deactivates ASCD operation.
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.
P1805 Brake switch ECM controls the electric throttle control actuator by regulating 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
P2100
P2103 Throttle 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.
P2101 Electric th rottle control
function 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.
DTC No. Detected items Engine operating condition in fail-safe mode
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

SYSTEMEC-569
< SYSTEM DESCRIPTION > [VQ35DE]
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*1: ECM determines the start signal status
by the signals of engine speed and battery voltage.
*2: This sensor is not used to contro l the engine system under normal conditions.
*3: Automatic air conditioning system
*4: Manual air conditioning system
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 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 position 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) Engine speed
*1
Fuel injection
& mixture ratio
control Fuel injector
Camshaft position sensor (PHASE) Piston position
Mass air flow sensor Amount of intake air
Intake air temperature sensor Intake air temperature
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Transmission range switch Gear position
Battery Battery voltage
*1
Knock sensor Engine knocking condition
Heated oxygen sensor 2
*2Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit) • VDC operation signal
• TCS operation signal
CAN communi-
cation
Power steering control module EPS operation signal
Combination meter Vehicle speed signal
A/C auto amp.
*3• A/C ON signal
• Blower fan ON signal
BCM
*4
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

EC-570
< SYSTEM DESCRIPTION >[VQ35DE]
SYSTEM
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov
ides the best air-fuel mixture ratio for drive ability and emission control.
The three way catalyst (manifold) can better reduce CO , HC and NOx emissions. This system uses A/F sen-
sor 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 A/F sensor 1, refer to
EC-552, "Air Fuel Ratio (A/F) Sensor 1"
. 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 th ree way catalyst (manifold). Even if the switching
characteristics of A/F 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 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 t he mixture ratio signal transmitted from A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM c ontrols 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 ai r 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 carri ed out over time to compensate for continual deviation
of the “short-term fuel trim” from the central value. Continual deviation will occur due to individual engine differ-
ences, wear over time and changes in the usage environment.
PBIB3020E
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EC-572
< SYSTEM DESCRIPTION >[VQ35DE]
SYSTEM
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Ignition order: 1 - 2 - 3 - 4 - 5 - 6
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 (PHASE) sig-
nal. Computing this information, ignition si gnals are transmitted to the power transistor.
During the following conditions, the ignition timing is re vised 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.
AIR CONDITIONING CUT CONTROL
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed
*
Ignition timing
control Ignition coil
(with power transistor)
Camshaft position sensor
(PHASE) Piston position
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
Transmission range switch Gear position
Battery Battery voltage
*
Knock sensor Engine knocking
Combination meter Vehicle speed CAN communi-
cation
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

SYSTEMEC-573
< SYSTEM DESCRIPTION > [VQ35DE]
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AIR CONDITIONING CUT CONTROL : System DescriptionINFOID:0000000009462517
SYSTEM DIAGRAM
*1: Automatic air conditioning system
*2: Manual air conditioning system
INPUT/OUTPUT SIGNAL CHART
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: Automatic air conditioning system
*3: Manual air conditioning system
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.
• When the accelerator pedal is fully depressed.
• 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.
JSBIA2685GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed
*1
Air conditioner
cut control IPDM E/R
↓
Air conditioner relay
↓
Compressor
Camshaft position sensor (PHASE)
Engine coolant temperature sensor Engine coolant temperature
Accelerator pedal position sensor Accelerator pedal position
Battery Battery voltage*1
Refrigerant pressure sensor Refrigerant pressure
Power steering control module EPS operation signal
CAN communi-
cation line
Combination meter Vehicle speed signal
A/C auto amp.
*2• A/C ON signal
• Blower fan ON signal
BCM
*3
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

SYSTEMEC-575
< SYSTEM DESCRIPTION > [VQ35DE]
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• More than 2 switches at ASCD steer
ing switch are pressed at the same time (Set speed will be cleared)
• Brake pedal is depressed
• Selector lever is in the N, P, R position
• Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed
• TCS system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.
• Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to t he normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing SET/COAST switch or RESUME/
ACCELERATE switch.
• Malfunction for some self-diagnoses regarding ASCD control: SET indicator will blink quickly.
If MAIN switch is turned to OFF while ASCD is acti vated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will maintain the new set speed.
RESUME OPERATION
When the RESUME/ACCELERATE switch is pressed afte r cancel operation other than pressing MAIN switch
is performed, vehicle speed will return to last set s peed. To resume vehicle set speed, vehicle condition must
meet following conditions.
• Brake pedal is released
• A/T selector lever is in the P and N positions
• Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
COOLING FAN CONTROL
COOLING FAN CONTROL : System DescriptionINFOID:0000000009462519
SYSTEM DIAGRAM
Automatic Air Conditioning System
JSBIA1589GB
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM

EC-576
< SYSTEM DESCRIPTION >[VQ35DE]
SYSTEM
Manual Air Conditioning System
INPUT/OUTPUT SIGNAL CHART
*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to ECM via the CAN communication line.
*3: Automatic air conditioning system
*4: Manual air conditioning system
SYSTEM DESCRIPTION
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant
pressure, and air conditioner ON signal. The control system has 4-step control [HIGH/MIDDLE/LOW/OFF].
JSBIA0321GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
Piston position
Cooling fan
control IPDM E/R
↓
Cooling fan relay
↓
Cooling fan motor
Engine coolant temperature sensor Engine coolant temperature
Refrigerant pressure sensor Refrigerant pressure
Battery Battery voltage*
1
Combination meter
Vehicle speed signal*2
A/C auto amp.*3• A/C ON signal
• Blower fan ON signal
BCM
*4
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM