EC-558
< SYSTEM DESCRIPTION >[VQ35DE]
COMPONENT PARTS
EVAP Canister Vent Control Valve
INFOID:0000000009462496
The EVAP canister vent control valve is located on the EVAP canis-
ter and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evaporative
emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the evapo-
rative emission control system is depressurized and allows “EVAP
Control System” diagnosis.
EVAP Control System Pressure SensorINFOID:0000000009462497
The EVAP control system pressure s ensor detects pressure in the
purge line. The sensor output voltage to the ECM increases as pres-
sure increases.
Fuel InjectorINFOID:0000000009462498
The fuel injector is a small, precise solenoid valve. When the ECM
supplies a ground to the fuel injector circuit, the coil in the fuel injec-
tor is energized. The energized coil pulls the ball valve back and
allows fuel to flow through the fuel injector into the intake manifold.
The amount of fuel injected depends upon the injection pulse dura-
tion. Pulse duration is the length of time the fuel injector remains
open. The ECM controls the injection pulse duration based on
engine fuel needs.
Fuel Level Sensor Unit and Fuel Pump (With Fuel Tank Temperature Sensor)
INFOID:0000000009462499
FUEL PUMP
The ECM activates the fuel pump for 1 second after the ignition
switch is turned ON to improve engine start ability. If the ECM
receives a engine speed signal from the camshaft position sensor
(PHASE), it knows that the engine is rotating, and causes the pump
to operate. If the engine speed signal is not received when the igni-
tion switch is ON, the engine stalls. The ECM stops pump operation
and prevents battery discharging, thereby improving safety. The
ECM does not directly drive the fuel pump. It sends the control signal
to the fuel pump control module, which in turn controls the fuel
pump.
JSBIA1337GB
PBIB3370E
PBIA9664J
JSBIA1282ZZ
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EC-560
< SYSTEM DESCRIPTION >[VQ35DE]
COMPONENT PARTS
Ignition Coil (With Power Transistor)
INFOID:0000000009462501
The ignition signal from the ECM is sent to and amplified by the
power transistor. The power transistor turns ON and OFF the ignition
coil primary circuit. This ON/OFF operation induces the proper high
voltage in the coil secondary circuit.
Intake Valve Timing Control Solenoid ValveINFOID:0000000009462502
Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing control solenoid valve changes the oil
amount and direction of flow through intake valve timing control unit
or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.
Knock SensorINFOID:0000000009462503
The knock sensor is attached to t he cylinder block. It senses engine
knocking using a piezoelectric element. A knocking vibration from
the cylinder block is sensed as vibrational pressure. This pressure is
converted into a voltage signal and sent to the ECM.
Malfunction Indicator lamp (MIL)INFOID:0000000009462504
Malfunction Indicator lamp (MIL) is located on the combination
meter.
MIL will illuminate when the ignition switch is turned ON without the
engine running. This is a bulb check.
When the engine is started, MIL should turn OFF. If the MIL remains
illuminated, the on board diagnosti c system has detected an engine
system malfunction.
For details, refer to EC-590, "Diagnosis Description"
.
Mass Air Flow Sensor (With In take Air Temperature Sensor)INFOID:0000000009462505
MASS AIR FLOW SENSOR
JPBIA4613ZZ
PBIB1842E
JSBIA0284ZZ
JSBIA1315ZZ
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SYSTEMEC-567
< SYSTEM DESCRIPTION > [VQ35DE]
C
D E
F
G H
I
J
K L
M A
EC
NP
O
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
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EC-568
< SYSTEM DESCRIPTION >[VQ35DE]
SYSTEM
MULTIPORT FUEL INJECTION SYSTEM
MULTIPORT FUEL INJECTION SY
STEM : System DescriptionINFOID:0000000009462515
SYSTEM DIAGRAM
*1: Automatic air conditioning system
*2: Manual air conditioning system
INPUT/OUTPUT SIGNAL CHART
P2119 Electric thro ttle control ac-
tuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is being driven, it slows down gradually because of fuel cut. After the
vehicle stops, the engine stalls.
The engine can restart in the N or P position, and engine speed will not exceed 1,000 rpm
or more.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal 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.
DTC No. Detected items Engine operating condition in fail-safe mode
JSBIA2683GB
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-604
< SYSTEM DESCRIPTION >[VQ35DE]
DIAGNOSIS SYSTEM (ECM)
EVAP SYS PRES VThe signal voltage of EVAP control
system pressure sensor is dis-
played.
FUEL LEVEL SE V ×The signal voltage of the fuel level
sensor is displayed.
START SIGNAL On/Off Indicates start signal status [On/Off]
computed by the ECM according to
the signals of engine speed and bat-
tery voltage. After starting the engine, [Off] is dis-
played regardless of the starter sig-
nal.
CLSD THL POS On/Off ××Indicates idle position [On/Off] com-
puted by ECM according to the ac-
celerator pedal position sensor
signal.
AIR COND SIG On/Off ××Indicates [On/Off] condition of the air
conditioner switch as determined by
the air conditioner signal.
PW/ST SIGNAL On/Off ××[On/Off] condition of the power
steering system (determined by the
signal voltage of the power steering
pressure sensor) is indicated.
LOAD SIGNAL On/Off ××Indicates [On/Off] condition from the
electrical load signal.
• On: Rear window defogger switch
is ON and/or lighting switch is in
2nd position.
• Off: Both rear window defogger
switch and lighting switch are
OFF.
IGNITION SW On/Off ××Indicates [On/Off] condition from ig-
nition switch signal.
HEATER FAN SW On/Off ×Indicates [On/Off] condition from the
heater fan switch signal.
BRAKE SW On/Off Indicates [On/Off] condition from the
stop lamp switch signal.
INJ PULSE-B1 msec Indicates the actual fuel injection
pulse width compensated by ECM
according to the input signals. When the engine is stopped, a cer-
tain computed value is indicated.
INJ PULSE-B2
IGN TIMING BTDC ×Indicates the ignition timing comput-
ed by ECM according to the input
signals. When the engine is stopped, a cer-
tain value is indicated.
CAL/LD VALUE % “Calculated load value” indicates the
value of the current air flow divided
by peak air flow.
MASS AIRFLOW g/s Indicates the mass air flow comput-
ed by ECM according to the signal
voltage of the mass air flow sensor.
PURG VOL C/V % • Indicates the EVAP canister purge
volume control solenoid valve
control value computed by the
ECM according to the input sig-
nals.
• The opening becomes larger as the value increases.
Monitored item Unit
Monitor Item Selec-
tion
Description Remarks
ECU IN-
PUT SIG- NALS MAIN-
SIG-
NALS
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EC-610
< SYSTEM DESCRIPTION >[VQ35DE]
DIAGNOSIS SYSTEM (ECM)
*: This function is not necessary in the usual service procedure.
ACTIVE TEST MODE
Test Item
WORK ITEM CONDITION USAGE
IDLE AIR VOL LEARN The idle air volume that keeps the engine within the specified range is memorized in ecm. When learning the idle air volume
EVAP SYSTEM CLOSE Close the EVAP canister vent control valve in order to make
EVAP system close under the following conditions.
• Ignition switch ON
• Engine not running
• Ambient temperature is above 0 °C (32 °F).
• No vacuum and no high pressure in EVAP system
• Fuel tank temperature is more than 0 °C (32 °F).
• Within 10 minutes after starting “EVAP SYSTEM CLOSE”
• When trying to execute “EVAP SYSTEM CLOSE” under
the condition except above, CONSULT will discontinue it
and display appropriate instruction.
NOTE:
When starting engine, CONSULT may display “BAT-
TERY VOLTAGE IS LOW. CHARGE BATTERY”, even in
using charged battery. When detecting EVAP vapor leak-
age in the EVAP system
FUEL PRESSURE RELEASE Fuel pu mp will stop by touching “START” during idling.
crank a few times after engine stalls. When releasing fuel pressure from
fuel line
SELF-LEARNING CONT The coefficient of self-learning control mixture ratio returns to the original coefficient. When clearing mixture ratio self-
learning value
TARGET IGN TIM ADJ* Idle condition When adjusting target ignition tim- ing
TARGET IDLE RPM ADJ* Idle condition When setting target idle speed
VIN REGISTRATION In this mode, VIN is registered in ECM When registering VIN in ECM
CLSD THL POS LEARN Ignition on and engine stopped. When learning the throttle valve
closed position
SAVING DATA FOR REPLC CPU In this mode, save data that is in ECM. When ECM replaced.
WRITING DATA FOR REPLC CPU In this mode, write data stored by “SAVING DATA FOR RE-
PLC CPU” in work support mode to ECM. When ECM replaced.
TEST ITEM CONDITION JUDGMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION • Engine: Return to the original
non-standard condition
• Change the amount of fuel injec- tion using CONSULT. If malfunctioning symptom disap-
pears, see CHECK ITEM. • Harness and connectors
• Fuel injector
• Air fuel ratio (A/F) sensor 1
ENG COOLANT
TEMP • Engine: Return to the original
non-standard condition
• Change the engine coolant tem- perature using CONSULT. If malfunctioning symptom disap-
pears, see CHECK ITEM. • Harness and connectors
• Engine coolant temperature sen-
sor
• Fuel injector
PURG VOL
CONT/V • Engine: After warming up, run en-
gine at 1,500 rpm.
• Change the EVAP canister purge volume control solenoid valve
opening percent using CON-
SULT. Engine speed changes according to
the opening percent. • Harness and connectors
• Solenoid valve
FUEL/T TEMP
SEN • Change the fuel tank temperature using CONSULT.
ALTERNATOR
DUTY •Engine: Idle
• Change duty ratio using CON-
SULT. Battery voltage changes.
• Harness and connectors
• IPDM E/R
•Alternator
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EC-614
< ECU DIAGNOSIS INFORMATION >[VQ35DE]
ECM
TP SEN 1-B1• Ignition switch: ON
(Engine stopped)
• Selector lever: D position Accelerator pedal: Fully re
leased More than 0.36 V
Accelerator pedal: Fully depressed Less than 4.75 V
TP SEN 2-B1*
1• Ignition switch: ON (Engine stopped)
• Selector lever: D position Accelerator pedal: Fully re
leased More than 0.36 V
Accelerator pedal: Fully depressed Less than 4.75 V
FUEL T/TMP SE Ignition switch: ON Indicates fuel tank tempera-
ture
EVAP SYS PRES Ignition switch: ON Approx. 1.8 - 4.8 V
FUEL LEVEL SE Ignition switch: ON Depending on fuel level of
fuel tank
START SIGNAL Ignition switch: ON → START → ON Off → On → Off
CLSD THL POS Ignition switch: ON
(Engine stopped) Accelerator pedal:
Fully released On
Accelerator pedal: Slightly depressed Off
AIR COND SIG Engine: After warming up, idle the
engine Air conditioner switch: OFF Off
Air conditioner switch: ON
(Compressor operates.) On
PW/ST SIGNAL Engine: After warming up, idle the
engine Steering wheel: Not being turned Off
Steering wheel: Being turned On
LOAD SIGNAL Ignition switch: ON Rear window defogger switch: ON
and/or
Lighting switch: 2nd position On
Rear window defogger switch and lighting
switch: OFF Off
IGNITION SW Ignition switch: ON → OFF → ON On → Off → On
HEATER FAN SW Engine: After warming up, idle the
engine Heater fan switch: ON On
Heater fan switch: OFF Off
BRAKE SW Ignition switch: ON Brake pedal: Fully released Off
Brake pedal: Slightly depressed On
INJ PULSE-B1 • Engine: After warming up
• Selector lever: P or N position
• Air conditioner switch: OFF
•No load Idle 2.0 - 3.0 msec
2,000 rpm 1.9 - 2.9 msec
INJ PULSE-B2 • Engine: After warming up
• Selector lever: P or N position
• Air conditioner switch: OFF
•No load Idle 2.0 - 3.0 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING • Engine: After warming up
• Selector lever: P or N position
• Air conditioner switch: OFF
•No load Idle 7 - 17
°BTDC
2,000 rpm 25 - 45 °BTDC
CAL/LD VALUE • Engine: After warming up
• Selector lever: P or N position
• Air conditioner switch: OFF
•No load Idle 5 - 35%
2,500 rpm 5 - 35%
MASS AIRFLOW • Engine: After warming up
• Selector lever: P or N position
• Air conditioner switch: OFF
•No load Idle 2.0 - 6.0 g/s
2,500 rpm 7.0 - 20.0 g/s
PURG VOL C/V • Engine: After warming up
• Selector lever: P or N position
• Air conditioner switch: OFF
•No load Idle
(Accelerator pedal: Not depressed even
slightly, after engine starting.) 0%
2,000 rpm —
Monitor Item Condition Values/Status
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