2009 NISSAN LATIO air condition

REFRIGERANT PRESSURE SENSOR
EC-1007
< SERVICE INFOMATION >
[MR TYPE 1] C
D E
F
G H
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K L
M A EC
NP
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Diagnosis Procedure
INFOID:00000000045375421.
CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower fan switch ON.
3. Check voltage between ECM terminal 41 and ground with CON- SULT-III or tester.
OK or NG OK >>
INSPECTION END
NG >> GO TO 2. 2.
CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower fan switch OFF.
2. Stop engine and turn ignition switch OFF.
3. Loosen and retighten ground screw on the body. Refer to EC-632, " Ground Inspection " .
OK or NG OK >> GO TO 3.
NG >> Repair or replace ground connections. 3.
CHECK REFRIGERANT PRESSURE SE NSOR POWER SUPPLY CIRCUIT
TERMI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
41 GR Refrigerant pressure sensor [Engine is running]
• Warm-up condition
• Both A/C switch and blower fan switch: ON
(Compressor operates) 1.0 - 4.0V
48 BR Sensor ground
(Refrigerant pressure sensor) [Engine is running]
• Warm-up condition
• Idle speed Approximately 0V
74 W Sensor power supply
(Refrigerant pressure sensor) [Ignition switch: ON]
Approximately 5VVoltage: 1.0 - 4.0V
PBIA9574J
:
Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15 BBIA0698E

Target idle speed
A/T No load* (in P or N position)
700 ± 50 rpm
CVT No load* (In P or N position)
M/T No load* (in Neutral position)
Air conditioner: ON A/T In P or N position
850 rpm or more
CVT In P or N position
M/T In Neutral position
Ignition timing A/T In P or N position
13 ± 5 ° BTDC
CVT In P or N position
M/T In Neutral position Calculated load value% (Using CONSULT-III or GST)
At idle 10 - 35
At 2,500 rpm 10 - 35Supply voltage
Battery voltage (11 - 14V)
Output voltage at idle 1.0 - 1.3*V
Mass air flow (Using CONSULT-III or GST) 1.0 - 4.0 g·m/sec at idle*
2.0 - 10.0 g·m/sec at 2,500 rpm* Temperature
°C ( °F) Resistance k Ω
25 (77) 1.800 - 2.200Temperature
°C ( °F) Resistance k Ω
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260

EC-1028< SERVICE INFOMATION >
[MR TYPE 2]
ENGINE CONTROL SYSTEM
*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). 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 (A/T and CVT models)
• High-load, high-speed operation

• During deceleration
• During high engine speed operation
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL) Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*3
Piston position
Fuel injection
& mixture ratio
control Fuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
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
Park/neutral position (PNP) switch Gear position
Battery Battery voltage*3
Knock sensor Engine knocking condition
EPS control unit Power steering operation*2
Heated oxygen sensor 2* 1
Density of oxygen in exhaust gas
Air conditioner switch Air conditioner operation*2
ABS actuator and electric unit (control unit)
Vehicle speed*2
Combination meter PBIB3020E

ENGINE CONTROL SYSTEM
EC-1029
< SERVICE INFOMATION >
[MR TYPE 2] C
D E
F
G H
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K L
M A EC
NP
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The mixture ratio feedback system provides the best air/
fuel mixture ratio for drivability and emission control.
The three way catalyst (manifold) can then better r educe CO, HC and NOx emissions. This system uses air
fuel ratio (A/F) 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 air
fuel ratio (A/F) sensor 1, refer to EC-1210 . 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 air fuel ratio (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 air fuel ratio (A/F) sensor 1 or its circuit
• Insufficient activation of air fuel ratio (A /F) sensor 1 at low engine coolant temperature
• High engine coolant temperature
• During warm-up
• After shifting from N to D (A/T and CVT models)
• When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL The mixture ratio feedback control system monitors the mixture ratio signal transmitted from air fuel ratio (A/F)
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 bas ic 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 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 air fuel ratio (A/F) sensor 1 i ndicates whether the mixture ratio is RICH or LEAN com-
pared to the theoretical value. The signal then triggers a r eduction 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.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycl e 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. SEF337W

EC-1048< SERVICE INFOMATION >
[MR TYPE 2]
POSITIVE CRANKCASE VENTILATION
POSITIVE CRANKCASE VENTILATION
Description INFOID:0000000004499921
SYSTEM DESCRIPTION
This system returns blow-by gas to the intake manifold.
The positive crankcase ventilation (PCV) valve is prov ided to conduct crankcase blow-by gas to the intake
manifold. During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the
PCV valve. Normally, the capacity of the valve is suff icient to handle any blow-by and a small amount of venti-
lating air. The ventilating air is then drawn from the air inlet tubes into the crankcase. In this process the air
passes through the hose connecting air inlet tubes to rocker cover.
Under full-throttle condition, the manifold vacuum is in sufficient to draw the blow-by flow through the valve.
The flow goes through the hose connection in the reverse direction.
On vehicles with an excessively high blow-by, the valve does not
meet the requirement. This is because some of the flow will go
through the hose connection to the air inlet tubes under all condi-
tions.
Component Inspection INFOID:0000000004499922
PCV (POSITIVE CRANKCASE VENTILATION) VALVE
With engine running at idle, remove PCV valve from rocker cover. A
properly working valve makes a hissing noise as air passes through
it. A strong vacuum should be felt immediately when a finger is
placed over valve inlet. JMBIA0686GB
PBIB1588E
PBIB1589E

EC-1062< SERVICE INFOMATION >
[MR TYPE 2]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
• Sea level
• Flat road
• Ambient air temperature: 20 - 30 °C (68 - 86 °F)
• Diagnosis is performed as quickly as possible under normal conditions.
Under different conditions [For example: ambient air temperature other than 20 - 30 °C (68 - 86 °F)], diagno-
sis may also be performed.
Pattern 1:
• The engine is started at the engine coolant temperature of −10 to 35 °C (14 to 95 °F)
(where the voltage between the ECM te rminal 38 and ground is 3.0 - 4.3V).
• The engine must be operated at idle speed until the engine coolant temperature is greater than 70°C
(158 °F) (where the voltage between the ECM te rminal 38 and ground is lower than 1.4V).
• The engine is started at the fuel tank temperature of warmer than 0 °C (32 °F) (where the voltage
between the ECM terminal 43 and ground is less than 4.1V).
Pattern 2:
• When steady-state driving is performed again even afte r it is interrupted, each diagnosis can be conducted.
In this case, the time required for diagnosis may be extended.
Pattern 3:
• Operate vehicle following the driving pattern shown in the figure.
• Release the accelerator pedal during decelerating vehicle speed
from 90 km/h (56 MPH) to 0 km/h (0 MPH).
Pattern 4:
• The accelerator pedal must be held very steady during steady-
state driving.
• If the accelerator pedal is moved, the test must be conducted all
over again.
*1: Depress the accelerator pedal until vehicle speed is 90 km/h (56
MPH), then release the accelerator pedal and keep it released for
more than 10 seconds. Depress the accelerator pedal until vehicle
speed is 90 km/h (56 MPH) again.
*2: Checking the vehicle speed with GST is advised.
Suggested Transmission Gear Po sition for A/T and CVT Models
Set the selector lever in the D position (CVT), D position with the overdrive switch turned ON (A/T).
Suggested upshift speeds for M/T models
Shown below are suggested vehicle speeds for shifting into a higher gear. These suggestions relate to fuel
economy and vehicle performance. Actual upshift speeds will vary according to road conditions, the weather
and individual driving habits.
Suggested Maximum Speed in Each Gear
Downshift to a lower gear if the engine is not running smoothly, or if you need to accelerate.
Do not exceed the maximum suggested speed (shown below) in any gear. For level road driving, use the high-
est gear suggested for that speed. Always observe post ed speed limits and drive according to the road condi-
tions to ensure safe operation. Do not over-rev the engine when shifting to a lower gear as it may cause
engine damage or loss of vehicle control. PBIB2244E
For normal accelera
tion in low alti-
tude areas
[less than 1,219 m (4,000 ft)]: For quick acceleration in low alti-
tude areas For high attitude areas
[over 1,219m (4,000 ft)]:
Gear change ACCEL shift point km/h (MPH) km/h (MPH) km/h (MPH)
1st to 2nd 13 (8) 24 (15) 24 (15)
2nd to 3rd 27 (17) 40 (25) 40 (25)
3rd to 4th 40 (25) 53 (33) 65 (40)
4th to 5th 58 (36) 71 (44) 73 (45)
5th to 6th 82 (51) 82 (51) 82 (51)

EC-1078< SERVICE INFOMATION >
[MR TYPE 2]
BASIC SERVICE PROCEDURE
BASIC SERVICE PROCEDURE
Basic Inspection INFOID:00000000044999291.
INSPECTION START
1. Check service records for any recent repairs that ma y indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
- Harness connectors for improper connections
- Wiring harness for improper connections, pinches and cut
- Vacuum hoses for splits, kinks and improper connections
- Hoses and ducts for leaks
- Air cleaner clogging
- Gasket
3. Confirm that electrical or mechanical loads are not applied.
- Headlamp switch is OFF.
- Air conditioner switch is OFF.
- Rear window defogger switch is OFF.
- Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no load.
6. Make sure that no DTC is displayed with CONSULT-III or GST.
OK or NG OK >> GO TO 3.
NG >> GO TO 2. 2.
REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3. 3.
CHECK TARGET IDLE SPEED
With CONSULT-III
1. Run engine at about 2,000 rpm for about 2 minutes under no load. SEF983U
SEF976U
SEF977U

Idle Air Volume Learning " .
VIN Registration INFOID:0000000004499932
DESCRIPTION
VIN Registration is an operation to registering VIN in ECM. It must be performed each time ECM is replaced.
NOTE:
Accurate VIN which is registered in ECM ma y be required for Inspection & Maintenance (I/M).
OPERATION PROCEDURE
With CONSULT-III
1. Check the VIN of the vehicle and note it. Refer to GI-43, " Model Variation " .
2. Turn ignition switch ON and engine stopped.
3. Select “VIN REGISTRATION ” in “WORK SUPPORT” mode.
4. Follow the instruction of CONSULT-III display.
Accelerator Pedal Released Position Learning INFOID:0000000004499933
DESCRIPTION
Accelerator Pedal Released Position Learning is an operati on to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal positi on sensor output signal. It must be performed each time
harness connector of accelerator pedal pos ition sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Clos ed Position Learning INFOID:0000000004499934
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to l earn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal . It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds. Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume Learning INFOID:0000000004499935
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:
• Each time electric throttle control actuator or ECM is replaced.
• Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the follo wing conditions are missed for even a moment.
• Battery voltage: More than 12.9V (At idle)
• Engine coolant temperature: 70 - 95 °C (158 - 203 °F)
• Park/neutral position (PNP) switch: ON
• Electric load switch: OFF